I like this idea: A game resource archive format (GRAF) Wiki. For the uninitiated, computer games often package much of their essential data– video data, audio clips, music, game maps, etc.– into monolithic archive files. This Wiki is an effort to document as many of those formats as possible. The Wiki was just released but it already boasts 600+ formats. If you see any holes, feel free to contribute.
How is this related to multimedia technology? Games often have FMV data packaged inside of such resource archives. I suspect the Wiki authors contacted me due to my meager (compared to their collection) document describing a handful of GRAFs.
If you are interested in hacking on a resource format that is not listed, check out their Definitive Guide To Exploring File Formats.