Some of the best discoveries on this journey have been towns that I knew nothing about beforehand, just serendipitous names on the map.

The place that stands out most in my mind is Jefferson, Texas, where I spent my birthday last December. It was everything a small country town should be, the kind of place where oldtimers sat gossiping on benches and shops were actually full of customers, rather than dying on their feet.

Another was Riverside, which I walked through today: a place with a real pride in its history. The outskirts were just typical southern Californian sprawl, but the downtown area had a real buzz. I sat opposite the Mission Inn, a nineteenth-century phantasmagoria of columns, domes and flying buttresses, sipped on a coffee, and watched the world go by.

Two children, waiting for their mother in a parked SUV a few feet away from me, hurled a crisp packet out of the window. It looked so out of place in the tidy street that I strode over, picked up, and thrust it back through the window. The children looked taken aback, and pointed accusingly at me when the mother returned, but the litter stayed in the car where it belonged.

The road out of town was lined with huge mature palms and clapboard houses, and I realised what a long time it had been since I last saw traditional American residential architecture.

Many larger towns and cities in this country lack any real heart. The most striking example I've seen recently has been Phoenix, which tries hard but whose downtown area consists of a few lacklustre shopping malls and empty streets that you can explore in twenty minutes; Dallas is another depressing example. So it's nice to see somewhere that bucks the trend.

I've finally got round to writing my 'How to walk across America' page - better late than never.

I've had quite a lot of emails from other people thinking of doing something similar and asking for advice, and I hope it will be helpful. But I also hope it will appeal to armchair travellers.

Back in August last year, when I was walking through Pennsylvania, I posted a picture of a roadsign saying 'California' on my blog. I wrote:

After more than a week of dallying, I've put on a burst of speed and made it all the way to California.No, not Arnie Schwarzenegger's land of perpetual sunshine, but the Pennsylvania town of the same name - but I did think one day, with luck, I'll walk past a similar sign and it really will be the Golden State.

Well, tomorrow I should be doing exactly that. I'm one mile short of the state line, on the banks of the Colorado river, and eagerly looking forward to seeing the Welcome to California sign. Back in August, this seemed like an event in the impossibly distant future, but now it's arrived. I wish time wouldn't pass so quickly.

After that, there's another long, empty stretch of Sonoran desert to look forward to, so you probably won't hear from me for a while.

I made a seventy-mile detour here (using my thumb rather than my feet), and I'm really glad I took the trouble.

The journey led me northwards along the Colorado river, a broad ribbon of deepest glinting turquoise pushing its way purposefully through empty desert and forming the boundary between Arizona and California.

Then the river widens into the 45-mile-long reservoir that is Lake Havasu, overlooked on its eastern shore by Lake Havasu City, a wholly artificial creation built in 1964 by chainsaw magnate Robert P. McCulloch.

Its centrepiece is the old London Bridge, dismantled in 1968 and brought here stone by stone.

I'd always been fascinated by the grandiosity of the project and the famous (though wholly untrue) legend that McCulloch thought he was buying the much more interesting Tower Bridge. The extraordinary story of what Guinness World Records describes as the biggest antique ever sold is recounted here.

I'd pictured the bridge as an incongruous tourist curiosity, feet planted in the sand, pollution-stained bricks fading in the broiling sun. In fact it still serves a very necessary purpose, spanning a busy canal and used by vehicles and pedestrians.

The bridge that replaced it is quite similar in design, and I could imagine a post-global-warming London in which speedboats full of bikini-clad tourists sipping exotic cocktails plied their way up and down a palm-fringed Thames.

It's a beautiful, elegant structure that fits perfectly into its new setting on the other side of the world. If bridges could think, this one would be dreaming of a bygone age, in which the sun never shone and bowler-hatted, grey-suited commuters scurried back and forth between London Bridge station and an assortment of banks and insurance companies.

I wish it a long and happy retirement.

If any of my Scrabble-playing friends are reading this, Quartzsite is easily the highest-scoring town of any I've visited - just imagine it mouthwateringly sprawled across two triple word scores. Shame about that redundant 'S' - the town was originally known as Quartzite, but the misspelled name somehow gained currency.

The four-day, 77-mile walk here across the Sonoran desert from the hot springs in Tonopah has been the most physically challenging stretch of the whole journey. It's been hot and empty, and I've had to carry up to eight litres of water. Also, I've avoided walking on the interstate, instead opting for tracks that follow it through the desert, some of them boulder-strewn switchbacks crisscrossed by deep ravines.

Everything is prickly, from the endless dense thickets of creosote bushes and palo verde trees to the dozens of barbed-wire fences, and my arms and legs are covered in scratches.

I've crossed thirty or forty fences; each time I have to decide whether to climb over, crawl underneath or gingerly part the wires and go through the middle. My backpack always gets thrown over the top in what I call the Barbed-Wire Bounce, in which I hold on till the very last moment to minimise the impact. So far, my laptop doesn't appear to have suffered any adverse consequences.

The Harquahala mountains have been another highlight of the walk: an immense cactus garden spanning a surprisingly rich gamut of sage and olive greens and stippled with scarlet ocotillo flowers like a Flanders poppyfield. Again, I'd have expected the area to be swarming with camera-clicking tourists, but the only sounds were the wind in my ears and the whine of tyres on asphalt a few hundred yards away.

Speaking of wind, the weather took a dramatic change for the worse today after weeks of constant heat and sunshine. Dark clouds massed over the mountaintops, the temperature plunged, and a vicious gale unleashed a phenomenon I've never experienced before and can only describe as a mudstorm, whipping up musty clouds of dust from the desert floor, mixing them with lashing rain and flinging the results into my face.

No matter how much water I carry, I usually have to ration myself at least slightly, and thirst is never far away. It's given me a special appreciation for little things I'd normally take for granted: the gurgle of water pumped through irrigation channels like the one I photographed in Phoenix the other day, the plink-plink of ice cubes rattling in my two thermoses as I walk, and even, last night in my tent, opening a tin of luscious pineapple rings in their own juice.

I'm awarding myself a day off tomorrow, metaphorically shedding my walking boots, donning my tourist hat and going off to explore a little bit of olde England in the Arizona desert. Watch this space.

I had two encounters with less than likeable creatures yesterday.

The first was in Subway, where I was buying my 31st footlong Veggie Delite on wheat with pepperjack cheese, all the veggies and lite mayonnaise. The woman in front of me was ordering for what I assume were her three teenage sons, and the assistant was just putting the finishing touches to a submarine sandwich when one of the sons muttered something in surly fashion to the mother.

'He doesn't like the look of that one,' she said to the assistant. 'Gimme a turkey one instead.'

Without a word or a moment's hesitation, the assistant dumped the sub into a bin at her feet and started making one with turkey.

'You should have charged them for the one you threw away,' I said to her afterwards.

'I know, I didn't think' she replied.

I wish I'd had the presence of mind to go after this spoilt little bastard, give him my card and say take a look at my blog, I'll be writing about you.

Later in the afternoon, I was scrambling up the bank of a dried-up river and listening to Andrew Marr's Start the Week on my MP3 player when I heard a sudden very loud chirring in my right ear, like a cricket on steroids. I took my headphones off and looked for the source of the noise.

On the sand beside me, about ten feet away, was a two-foot rattlesnake, head reared and tail in furious motion. I stopped just long enough to snap a few pictures and hurried off, not leaving my card to tell the snake I'd be writing about it.


Arizonans reading this will probably say what's the big deal, I clear half a dozen of the things off my front porch every morning, but it was the first time in ages that I'd felt adrenaline coursing through my veins.

Later on, darkness fell and I got hopelessly lost for a while. Funnily enough, I walked past another three rattlers: I'd never seen one before, and now they were everywhere.

As a respite from all this stress, I've spent much of today in a piping hot bath with water streaming over the sides. I stayed in El Dorado hot springs, only a quarter of a mile from the interstate but half a world away, and even on Easter Day there were only a dozen people there. I wish I could have had a place like this at 100-mile intervals all the way across the country to rest my aching legs and wash the dust away.

I'm now on the very farthest western edge of Phoenix, and once again I've enjoyed seeing a bustling downtown street metamorphosing ever so gradually into a sleepy country road.

It's taken me three days to walk across the city, but it's a beautiful place, and I haven't seen so much dazzling greenery since I was in Florida at Christmas: shady parks, nail-scissored golf courses, and mile after mile of flourishing crops.



Trouble is, this is supposed to be a desert city, and all this verdancy has been achieved by irrigation. Phoenix has been wracked by drought for the past twelve years, its water supplies are believed to be adequate for another twenty, and today's study by the Intergovernmental Panel on Climate Change predicts that areas like the Southwest could soon return to the dustbowl conditions of the 1930s. These are all the hallmarks of an environmental disaster in the making.

On a lighter note, I've noticed in the past week or so that when I tell people what I'm doing, they no longer say, 'Wow, you've got a long ways to go'. They say, 'Wow, you're almost there', which I find immensely heartening, even though I still have another 350 miles and anything could still happen. A friend of Pam's stubbed her toe and broke it the other day, and I thought selfishly: ouch, that could have been me.

This afternoon, a guy did a U-turn and stopped beside me: 'Are you going to the coast?' he asked, and I told him yes. 'Well, hop in,' he said. 'I'm going to Newport Beach in about an hour.' Newport Beach is a suburb of Los Angeles. I thanked him and explained that I was walking; it was a six-hour journey for him, but several more weeks for me.

And then, as I arrived at my motel tonight, I saw this and was really excited. It was the first time I'd seen the City of Angels mentioned on a roadsign, and it really felt like the end was within my grasp.

Do any of you kind people have a couple of thousand dollars, or the equivalent in another freely negotiable currency, or any smaller amount, burning a hole in your pocket? This is a serious question.

If you do, fellow coast-to-coast walker Stuart Hamilton could put it to good use. Remember he was diagnosed with testicular cancer just before he went home to England for a winter break? Well, he's fine now, and he and Dave are about to resume their walk. He explains here why he could really use the money. If you can spare something, please contact him direct. I cannot imagine a better cause, or a nicer person, to donate your hard-earned readies to.

1. According to an analysis of search engine requests by the fascinating ePodunk.com, Phoenix is the ninth most frequently misspelled US city. Tucson is no. 2 on the list. The others in the top ten, in decreasing order of frequency, are Pittsburgh, Cincinnati, Albuquerque, Culpeper, Asheville, Worcester, Manhattan, and Niagara Falls.
2. A person who lives in Phoenix is called a Phoenician.
3. Phoenix, and most of the rest of Arizona, don't put their clocks forward in summer. They don't need any more sunshine than they have already.
4. The average number of days on which the temperature exceeds 100F (38C) is 89. In 1989, it was 143.
5. Because of its huge sprawl, Phoenix is the tenth most dangerous US city in which to walk.
6. Perhaps for this reason, paramedics are the city's fastest-growing occupation.
7. The University of Phoenix, the country's largest private university, is notorious for its alleged poor-quality teaching, its 16% graduation rate, and its use of spam and popups to recruit students.
8. Maricopa county, in which Phoenix is located, is the nation's fastest-growing county. Its population expanded by 43% in the ten years to 2005, reaching 3.6 million.
9. The real name of actor River Phoenix was River Jude Bottom.
10. I met a female novelist in Texas called River Jordan. Sorry, not relevant, but it's just reminded me.

Great news! William McGonagall is alive and well, and now has a part-time copywriting job at McDonald's, where he penned the timeless ode I found on my placemat tonight.

Breakfast is the meal that defines your day,
don't let a juice box and granola bar steer the way.
Go with a McGriddles® sandwich or a platter perhaps,
cold meals are tasteless and boring; they're for saps.
Next, pair your food with coffee for the ultimate taste,
it's so good you'll leave nary a bite nor sip to waste.

If you get a moment, do have a listen to my podcasts by clicking on the link above. You don't need an MP3 player; you can listen to them on your computer.

Actually, they're not mine. I was asked to do a regular podcast several months ago by Podshow.com and Jack Cumming, my contact at the Association for International Cancer Research, but I said I wasn't sure I could make the commitment.

So Jack went off to AICR's lavishly equipped recording studio and did them himself, reading selected nuggets from my blog in his mellifluous Fifeshire (that's in Scotland) tones and adding comments of his own. I think he's done a lovely job, and he's still churning out more.

On a different note, I hope the heat isn't going to be a problem for the rest of this trip. It was 90F (32C) today, and although I wore my wide-brimmed hat and plastered myself with sunscreen as I do every day, I was still exhausted and dehydrated by the time I arrived at my destination. I had a fit of the shivers in the restaurant just now, and I must be the only person in Arizona to have the heating on in my room.

I'm used to temperatures like these from last summer - the hottest I experienced, ironically, was in Frostburg, PA, when it reached 99F (37C) - but that was the densely populated east coast and there were shops and vending machines every five minutes. Here, water supplies need rather more careful planning.

Things are looking up on the social front, though. After the Empty Quarter of Arkansas, Texas and New Mexico, I'm meeting a lot more people. I've got used to the solitude and learned to enjoy my own company, but I still find that a steady succession of encounters with strangers makes the day pass a lot more quickly.

I also have two new forms of vegetation to add to my collection. I first saw saguaro cacti growing wild on a hillside outside Tucson, and they're now a ubiquitous feature of the landscape, often with the regulation Mexican dozing beneath their outspread arms.


The other is palm trees, which made their debut in the little town of Picacho. Normally I would have found it a rather funereal place, with its junkshops, fleabitten dogs chained to posts in every front garden, defunct motels and mournful country music wailing from someone's stereo, but the palms and the cacti and the dazzling Arizona sunshine somehow redeemed it.


The bit about the lavishly equipped recording studio was a joke, by the way. In keeping with their status as charity workers, everyone at AICR wears threadbare tweeds, pays £5 a month in rent for the privilege of living in a tumbledown, roofless highland croft, and travels to work by horse and cart, all so that every penny of your donations goes to a good cause.