Another “so I don’t forget it” post.
Converting Quicktime (.mov) files to Ogg Theora (.ogv) is now rather simple (although takes a while).
Firstly, install ffmpeg2theora (it should be available for most distros).
Then just launch it from the command line. The syntax is:
ffmpeg2theora name_of_file.mov
Or to do a whole directory:
ffmpeg2theora *.mov
Easy.