Big news: The Free Software Foundation has released GNU FDL (Free Documentation Licence) version 1.3, a minor update, but a big step towards legal interoperability of free and open licences. This interoperability had been requested by the Wikimedia Foundation a while ago.
It allows FDL licensed Wikis, like Wikipedia, under certain conditions, to republish their content under a Creative Commons licence, namely the CC BY-SA version 3.0.
More info on the Creative Commons blog and a good FAQ over at GNU/Free Software Foundation. Btw, have you seen Stephen Fry explain Free Software?
Luxcommons asbl 