Star Wars: Revelations

Extremely impressive 40-minute long fan movie, set between Episodes III and IV. The acting is slightly less than professional--certainly it's no worse than Hayden Christensen's bumbling attempts--but the production quality is easily at the silver-screen level. Sound, music, special effects, space battles... they all look like they were done in a very expensive post-production studio, but it's a purely volunteer effort by a lot of very talented people.

You can find a Quicktime direct link here, but demand for the movie is currently very high, so if that mirror is down, you can look through these mirrors to find another. It's well worth the download time.

Additionally, C-Net has posted an in-depth article about the production of the movie.