[IMAGE1] Outside the café where I'm chatting to Bill Bryson, a passing student notices the avuncular writer, points madly at her bag and grins. I'm bemused, but Bryson can interpret such gestures: "She probably has one of my books in her bag," he explains. "I'm always recognised more when I've recently been on TV, but I much prefer anonymity, both as a person and for my work. I'd hate to be as recognisable as David Beckham."

Bryson experienced celebrity of a different nature on his first trip to Kenya last autumn. Arriving at a remote settlement with staff from the charity CARE, he was feted by villagers who didn't know him but who were ecstatically grateful for a well CARE had dug, saving the womenfolk a daily seven-hour round trip to fetch water. "There was so much misdirected gratitude - as if I'd paid for and dug the well myself," he smiles. "But it was wonderful to see how this simple pump had changed people's lives."

The journey to Africa resulted from a chance encounter in Hyde Park, when CARE manager Dan McLean spotted Bryson and asked whether he'd consider visiting some development projects and writing about them. Bryson agreed and was given a whirlwind tour of Kenya, incorporating Nairobi, the coast, a Somali refugee camp and settlements by Lake Victoria. The result is a colourful little book which hit the shelves before Christmas, illustrated with photos of subjects that don't make the tourist brochures. The proceeds go entirely to CARE. Bill Bryson's African Diary chronicles his week in Kenya in a text spiked with wit but which also cleverly exposes the main challenges faced by aid agencies. A writer known largely for humour initially seems an odd choice for such a serious task, but Bryson's popularity and accessibility are just what's needed to engage a donor-fatigued audience. Between the funny parts, his writing has always demonstrated perspicacity. He can penetrate the heart of an issue and tell it how it is. He'd only visited mainland Africa once before, on a book tour to South Africa, where his audiences were largely white and he remained cocooned from local daily life. The Diary opens with a humorous take on everything that could go wrong on the trip, but he knew he was in good hands. His main fear was rational: "I'd never knowingly been to a malarial area before," he explains. As a result, he slept so lathered in insect repellent that he sounded "like two strips of parting Velcro each time I roll over in bed."

Bryson may have been ready for mosquitoes, but he wasn't prepared for the deprivation he encountered. "I'd seen poverty before, but had never been permitted to stare at it. Initially I thought the book wouldn't be funny because what I'd seen wasn't funny, but then I considered expectations and the fact that people might receive it for Christmas, and I thought they have a right not to be depressed by what's in their stocking. But I'd understand if readers think the humour's forced in places."

They might, but there are moments of genuine amusement and his humour is never deployed inappropriately. Bryson's main achievement is to humanise everyone he meets, to make us realise fully that the anonymous statistics concerning poverty and aid describe millions of individuals just like ourselves. In Kibera, one of Nairobi's notorious townships - a giant cesspit containing 700,000 people living without sanitation - he was escorted by a resident originally from the countryside. What, Bryson queried, could be so bad about life in the country that anyone would choose to move here? The man's answer could have come from any Western parent: "All these people, they are here for their children." The countryside is pleasant, he explained, but offers no employment, so people can't afford school fees. "In the city, if you work hard and are lucky, you can educate your children and maybe they will have a better life." A Kenyan CARE employee added: "People here will do anything to improve the lot of their children."

"Kenya's people are just you and me in a different situation," believes Bryson. "I've met some Westerners with the misplaced notion that somehow people live this way because they deserve it. But it's not because of anything they've done or failed to do - you and I could so easily be in the same position. It's not due to any virtue that we're living here; we're just lucky to be born into different circumstances. The fact that we're all equal individuals really hit home while I was there." Despite the conditions he witnessed, Bryson is optimistic about Kenya's (and Africa's) potential. "I was surprised and heartened by Kenya's people," he admits. "They're so resourceful and optimistic, and the basic infrastructure's there. It only needs tweaking to get it right. With ten years of good governance, you could have another South Korea or Singapore." The book is frank about the wilful corruption and mismanagement that created Kenya's current situation: the presidential mansion overlooks Kibera, yet former President Moi's government ignored its residents' plight; a road in the west remains untarred because officials pocketed the donor funding.

Was there anything he found truly hopeless? "The Somali refugee camp was really depressing. As things stand, its 134,000 residents have no future. They can't leave and flood into Kenya, yet Somalia's not safe. There are 18-year-olds who have never known anything other than life behind wire. They might be 50 by the time they get out." It is indigenous Africa that excites him most. He is evidently touched by its people and is rapturous about Kenya's unparalleled palaeontological riches: "I see what people mean by the ‘Africa Bug'. There's the light, the beauty - obvious things - but I think it's also because here's where humans come from. Visiting the Rift Valley was like coming home. I think perhaps our genes feel happy because they're returning to where we evolved. Wow, it made me shiver!"

He dismisses Karen Blixen's house and lunch with some "jolly white farmers". "I've never understood colonialism. It seems there was an inadvertent evil built into a system where skin colour meant certain people would only ever be servants." Yet he appreciates Nairobi's cosmopolitan make-up. "I'm a great believer in multiculturalism. I've never understood why it upsets people so much, when it just makes life better, more interesting. Just look at food in Britain."

Bryson's face looks built for smiling, yet there's an underlying gravity. His African Diary is about more than selling copies to raise funds. It conveys serious messages about the challenges charities face. He dashes the common misperception that money donated to agencies like CARE goes to corrupt officials rather than into development projects. And the stories of people he meets emphasise a new aid creed of helping people to help themselves: women whose small businesses flourish thanks to CARE's micro-credit bank; a "model farmer" who CARE has educated in the latest agricultural methods so he can teach his neighbours. Just like us, Africans would prefer to be self-reliant, independent of handouts. Bryson also learned basic aid protocol. Slipping momentarily into book-speak, he explains: "At the refugee camp, I asked naively why they weren't doing more, why the people weren't being given TV and cup-cakes. CARE staff looked at me as if I knew nothing and gently explained that even if funds were available (which they aren't), you can't make camp conditions better than in a host country or everyone would want to be a refugee. I came back with a profound appreciation of the human scale of Africa's problems."

Would he return to Africa and write more about it? "Yes, I'd like time to absorb it and do background reading, not have to write about it in three weeks," he says, adding unexpectedly for such a veteran solo traveller that he'd like to go with someone who knew the continent. "It was so good to travel with CARE because whenever I didn't know something, I just asked and received an immediate answer. It was also reassuring to have people looking after me, and luxury to have companions for meals and drinks. It was ten times more rewarding than if I'd gone on my own." He's deeply saddened by the terrorist attacks on the Kenyan coast last November. "Kenya's beaches match the Seychelles', yet the prospects for tourism in the Seychelles are strong while Kenya's are bleak. The bombing's so unfair, but overall the country's situation isn't hopeless. Kenya's people are bright, engaged, alert and funny. I was in South Korea for the World Cup - did you know that after WWII, the country was such a basket case that America was considering installing a Japanese caretaker government, even though they'd just evicted Japan, simply because the Japanese could at least run a country? Now look at the success South Korea's become. There's no reason why Kenya - or other African countries - can't do it too."

Whether the devastating effect of AIDS on the potential work-force would permit such rapid development is another question. Readers of his African Diary can only hope Bryson's right - and in the meantime, follow his example in helping organisations such as CARE improve life for Africa's people.