Fred Benenson has released a Creative Commons License Facebook application.
Here's an excerpt from the announcement:
Last weekend I spent Saturday morning writing the Creative Commons License Application for Facebook. The premise is simple: installing the application allows Facebook users choose and place a CC license badge on their profile page indicating which license they want their content to be available under. Alongside the badge is text that explains what content (Photos, Videos and Status & Profile text are currently available as options) is licensed.
This surrounding text also contains RDFa, though this is of limited utility to search engines since Facebook profiles are not yet publicly indexed.