What is it? A wooden receptacle into which honest members of the public put money, writes Kevin Courtney

Where will you find one? You'll often find one at a car park, historical site or public convenience, where there is no attendant available. Just drop some cash into the box before you leave. Any amount will do - whatever you think is fair.

That's very trusting. Last month, an honesty box was installed in Edinburgh City Chambers, and councillors were asked to put money in to pay for their lunch. The box was replaced after just a few days when it was found that the contents came up short by about 10 quid.

Stingy Scots civil servants! So what's the big deal? This week, an honesty box goes up that has massive implications for the entire music industry, and could net millions from trustworthy customers.

Must be a big box. The rock group Radiohead, currently out of contract, are releasing their new album, In Rainbows, tomorrow, but for the time being it will be available on download only through their website, www.inrainbows.com. The band have set up an online honesty box, into which you key in the amount you wish to pay for the album. So, if you think it's another masterpiece that pushes the envelope of rock even further outwards, you can lob in, say, a tenner. However, if you think it's another self-indulgent, tuneless load of twiddly twaddle, you are free to pay just a measly few pence. It's completely up to you.

Such freedom! I feel quite dizzy. So will record company executives who have all 10 fingers already stuck in the overflowing dam of downloads. Radiohead's move could force many in the business to start thinking outside the box.

Anyone else embedding an honesty box in their website? Social networking site Facebook has one available, which you can install on your profile. Instead of putting money in, though, you write in a message to one of your friends telling them what you really think of them. It's completely anonymous, say Facebook, so when you tell someone they smell bad or their favourite band (Radiohead) is crap, they won't know who sent it.

Who would be brave enough to read that? Tory leader David Cameron, perhaps. He admitted last week in his speech to his party conference that he looked himself up on Facebook. Among the 265 groups dedicated to the Conservative leader are "David Cameron is a Hottie" and "Will Someone Please Run Over David Cameron?"

Try at work: Downloading has forced us to cut costs, so we've set up an honesty box to pay your salary.

Try at home: Darling, what's that honesty box doing beside the bed?