Some suggestions:
Put a little synopsis of each machine like the one trygve has above (or is that what the description field is?). Or perhaps break it down into stats. Memory, speed, overclock, monitor, liquid helium/nitrogen cooling, etc.
Put the rating options right there on the front page, and have it advance you to the next picture.
And, probably most of the people that you are targetting to frequent this site probably have 20,000x16,000 resolution but at my res i can't see the whole front page for the computer, and especially the rating window I have to scroll for. I think a much more compact one would be sufficient unless you have visitors from florida.
nice work so far!