I saw via Groklaw’s news picks a plea for help over at the FSF. What they are looking for is the kind of advocacy and education work I actually rather enjoy. Rather than just declaiming creators should use free video formats, like WebM and Ogg Theora, they want help in answering specific questions that arise from the actual people trying to do so.
Logistically, it involves being subscribed to our low-traffic GNU audio-video team mailing list (firstname.lastname@example.org) and responding to the questions and problem reports sent to the list by people making the videos. In the remaining time, you could assist with the written documentation we are working on to help guide people through the video production process.
My own experience falls much more on the audio side but I may sign up anyway. Often the simplest questions go unanswered causing a potential adopter of free and open technology to give up, permanently writing it off as a waste. I see mailing list archive after forum littered with these kinds of questions that would take the bare minimum effort to answer.
If you have deeper experience with any part of video production using free software and encoding into unencumbered formats, consider signing up as well. Having been both a provider and recipient of these kinds of answers, I cannot impress on you enough how far a little bit of help really goes.