One of the current popular links at spid.ero.us (a great resource in itself) is this good and very straight-forward vlog (video blogging) tutorial. The tutorial takes you through the steps of creating and posting a video blog entry using fairly common tools (e.g., iMovie or MS MovieMaker, Blogger account). It also shows the process of hosting the video file at OurMedia.org.
This is a nicely setup resource that is straightforward for the “average” user (whatever that may mean anymore). The tools used would be common to most classrooms that I can think of, so technically, there wouldn’t be a huge barrier to having students participate in something like this. Of course, school politics and policy is a whole separate issue (see related).