PledgeBank is an excellent site, part of the MySociety network, where you can make a public pledge to do something if a certain number of other people will pledge to do the same.
That’s not to say there aren’t some strange pledges. Take this one, a natty fascist number, in which people are proposing the slaughter of the elderly, the forcible sterilisation of poor people and restricting the right to vote to (and I paraphrase) pointlessly angry ill-educated bigots like me.
So far, so FreeRepublic, you might think. But what is the ‘people who signed this pledge also signed…’ pledge? Lobbying their employers for fair trade coffee! Welfare: It’s OK for coffee-growers, but not for anyone else.