Zanesville, Ohio. Exactly 500 miles.

My much-loved but pedantic friend Tim has reminded me that I've also been to Zermatt, Switzerland and Zeebrugge, Belgium. Well, OK, but you get the idea.

Anyway, those hardworking people in the coincidences department have been working overtime, and today they pulled off a real coup. As I walked out of Norwich, I saw four hikers heading towards me. Seeing anyone using their legs as a means of propulsion is rare enough in this country, but these were the first people in seven weeks who were actually walking on the road for its own sake, rather than because their car had broken down or something.

We stopped to chat, and I learned that they were part of a team of seven progressive Christians hiking from Phoenix to Washington DC in a project called CrossWalkAmerica, seeking to encourage greater tolerance and offer an alternative to religious fundamentalism. They'd notched up 2,100 miles since Easter Day, so the end was in sight. I particularly envied them for their support vehicle, which allowed them to concentrate on the thing that mattered most: putting one leg in front of the other. They invited me to dinner in the evening, I accepted with pleasure, and we said our farewells.

Left to right: Stephen Yarbrough, from Zanesville, spending a day with the walkers; Eric Elnes; Rebecca Glenn; Mark Creek-Water, who has been drinking from muddy brown rivers for the past ten years with no significant side effects.

Less than a minute later, as I was picking up my backpack and moving off, two cyclists rode up. "Are you crossing America for cancer research?" one of them asked. "So are we."

Jacob and Ezra Pierce are part of a six-strong group of college students, pedalling from San Francisco to Baltimore to raise money for the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins. Three of them are from Britain's second best university.

Actually, I'm not sure "pedalling" is quite the right verb, evoking, as it does, little old ladies wobbling their way to village cricket matches. No, these guys are the real deal, streaking across the prairies at a phenomenal 600 miles a week, their bloodstreams untainted by even the merest hint of performance-enhancing substances. They left SF on 3 July, and expect to cross the finishing line on 14 or 15 August.

These people really put me in my place. Any reasonably fit person can walk across America if they want to, but not everyone can cycle it in less than six weeks. As if that weren't enough, the prose on their website is as finely crafted as a Shimano cotterless titanium alloy crankpin.

Dinner with my fellow walkers was a delight. We ate in the grounds of a church in Zanesville, compared notes on crucial issues of the day like blisters, daily mileages, and objects we'd found beside the road, and enjoyed a tour of this fascinating city.