An IT worker is trying to raise money for a homelessness charity starting with only a cardboard box.
Jason Hill, an IT worker in London, hopes to exchange the box for a more valuable item, which he will trade up until he has something of "significant value" to auction for the Big Issue Foundation.
Hill had the idea after finding it difficult to get sponsorship for a London-to-Paris bike ride for the charity.
"I thought of starting with something of minimal value," he said. "Most people will swap something because they don't feel they are giving away a substantial amount of money."
Hill set up a website called the Cardboard Box Project. So far, he has swapped the box for a book on DIY, which was then exchanged for a bottle of Cardhu single-malt whisky worth about £35.
"The struggle is letting people know about it," he said. "When it gets out there, it should pick up."