Long exposure test with my new 1d MII. This was 55 minutes at f/7.1 using a tripod and shutter remote. I should of been using a wider aperture, but I had originally planned on doing a 120 minutes shot.
The 20D is supposed to be better and there is even a modified version of the 20D (20Da) that is better for night photography. The best thing to do, would be to take several shorter exposures and just stack the images together in photoshop.