This idea has me pretty excited: what about students filming or audio recording lectures and uploading them as supplementary material for textbooks? The audio/video material will itself not be immediately wiki-able but could be available on the site for reference and future editing. Anyone out there know of intellectual property questions? Is there any problem taping a lecture and uploading it? Does it depend on whether the teacher/prof gives permission, or the school, or what?
My mind is positively busting with the possibilities of science lectures available on wikibooks. Some people learn best by reading, others by listening, others by seeing ... If we can get audio or video of lectures online that will be like having a downloadable classroom, where you can get all of the classroom experience except the immediate opportunity to ask questions.
Karl