Scott Macauley of FilmmakerMagBlog tipped me to this. He writes:
Peter Sunde, one of the founders of the torrent site The Pirate Bay, has launched his venture, Flattr. Basically, on a monthly basis you commit to an amount of money that you'll disperse to content creators. Then, as the month goes by, you click on their Flattr buttons and at the end of the month the service divvies up your funds and gives an equal amount to each person you've clicked.