If you needed an excuse to be kind, you have one now

‘THEY still call me The Leader," admits Danny Wallace. "But it’s all tongue-in-cheek. I’m really just the same as any other speccy bloke."

He’s not, though. If you bump into him, he’ll probably offer you a chocolate bar. Or compliment your shoes. Because that’s his way. The way of the Karma Army, the benign cult he accidentally invented in a moment of inspired boredom. A collective - "not a cult" - of 7,500 ‘joinees’ who gather in pubs, bookshops and on street corners around the world to perform random acts of kindness (RAOK) for strangers every Friday. Or whenever they feel like it. Less an organised religion than a haphazard assemblage of hit-and-run humanists, they send unsolicited wedding presents to America, buy unbidden pints in Australia and make old ladies smile in China. They’re particularly big in Belgium.

Recently updated and with a letter of praise from Tony Blair, Join Me, the book of Wallace’s extraordinary adventures in altruism is subtitled "The True Story of a Man Who Started a Cult by Accident". But it could be subtitled: "Cult leadership behind your girlfriend’s back." He knew she would disapprove of this "stupid boy-project", which began when the 27-year-old writer and TV producer discovered that his Great-uncle Gallus, a recently departed Swiss farmer, once founded a commune. Of three people. (Less a commune, more a flatshare, as Wallace observes). Determined to better this, Wallace placed an advert in Loot simply asking people to "join" him by sending in a passport photo.

To his surprise, a man named Chris Jones responded and persuaded his flatmate to join too. Pretty soon, more photos arrived and the website, www.join-me.co.uk, was set up. As the number of joinees approached triple figures, Wallace realised the project required a purpose and so "Good Fridays" were born. Since then, Join Me’s numbers have rocketed, spawning an official song, all manner of tacky merchandise and celebrity joinees including Richard and Judy, Emma Freud, Richard Curtis and Mackenzie Crook. As Wallace is the former flatmate of comedian Dave Gorman, and co-wrote his pal’s Edinburgh Festival 2000 hit show "Are You Dave Gorman?", it is no surprise to hear that there is also a screenplay in development.

My first audience with The Leader came in Edinburgh recently when I embedded myself with the Karma Army’s Scottish collective in the Pear Tree beer garden. Led by the Reverend Gareth Saunders, who maintains Join Me’s aims are in keeping with his faith, they are a disparate bunch brought together by the social cohesion of performing nice pranks. A series of RAOK had been planned for the Royal Mile when a phone call arrived from Wallace in London. Passed along the 14-strong band of students, teachers, pyjama salesmen and women dressed as fairies, he informed them that over 200 joinees had been dispatched from a pub in London to perform a string of good deeds across the capital, culminating in the purchase of a farm for an elderly Thai gentleman.

"It was great," Wallace enthused afterwards. "Quite an intimate occasion because I’d rented an entire bar, a real joinee crush. Even if they were coming on their own and had never met anyone before, they instantly made friends. It was like a school reunion of people who didn’t go to school together."

A global cult means global travel. Wallace’s current book reading tour of the UK follows similar jaunts in the US and Australia and his missions to meet and recruit joinees across Europe.

"Everyone likes to be nice and have nice things done to them. But the only sort of clubs that existed for this type of thing before were religious. I’m just saying do something nice on a Friday, that’s enough to give people confidence, because they know on that day thousands of other people around the world are being nice as well. It’s an excuse to be kind."