Observations: Will this book change your life?

The title of their latest publication, This Book Will Change Your Life, seems somewhat presumptuous. But authors Ben Carey and Henrik Delehag, aka "Benrik", can prove its veracity: since 2003 they've published This Diary Will Change Your Life, each edition containing 365 suggested tasks that, if enacted, will change the reader's life – not necessarily for the better. More than 6,000 readers have used Benrik's website (benrik.co.uk) to blog about their experiences after following the instructions: at least one has been arrested and one fired; two were married, then separated; another opened a restaurant in his living room.

The book is a collection of greatest hits from the last six years, featuring such classics as "Today, do something radical with your hair", "Today, glorify terrorism" and "Today, threaten a foreign country". Each of Benrik's challenges comes with its own artwork, the best of which will be exhibited at KK Outlet in London, from 27 October to 1 November. "The tasks have to be life-changing at some level," Carey explains, "and something people can realistically go out and do. They have to be thought-provoking and original. But if they're funny enough we'll ignore the rules."

Carey and Delehag are former advertising creatives who became disillusioned. "We made an ad for a new Hula Hoops product called 'Shocks', in which electric eels had been put in the water supply and would come out of toilets and shock people. We had hundreds of complaints from parents. The ad was taken off the air, and we decided to move on."

Published by Boxtree, £12.99