I have bought a new camera at Astronomiser. They sell astronomy modified cameras with a one year guarantee, so I am now the proud owner of a Canon 550D with no infrared filter. This should make photographing the red hydrogen alpha light from nebulae much easier.
I did some tests shots last night, and I am really amazed at how good the photos turned out. Of course, there are five years of development between the Canon 550D and my old Canon 350D. Looking through my photos I noticed something interesting. The brightest star trails had a blue line on one side and a red line on the other side: Chromatic aberration! Sure, it is not a desirable effect, but it was actually kind of cool to see something I have learned about in class. :)