DVD Tracks gives you a chance to make and distribute your own DVD commentary track. Inspired by Roger Ebert's suggestion, the site lets you manage links to your own audio files (which you host somewhere else), and browse and access other people's commentaries. Only one commentary so far, excellent to see the site's creator leading by example.

This might go the way of The Sims Movie Challenge due to the amount of effort involved (Neale got a good amount of publicity and 0 entries), but it's still a neat idea.