Also, try checking out
DealMac. They update just about daily on deals around the internet.
One of the tricks to buying computers today is to realize that, for 90% of the time you will spend on the machine, a new machine is way overpowered for the tasks you're going to throw at it. I mean, it doesn't take much power to skim through TFP or write email or listen to music. I'm a graphic design student and, for less than the price of a killer PowerMac setup, I can get a 17" iMac and 12' iBook which is ample power for nearly everything I do. iMac for working at home, and iBook for working elsewhere (I love working at coffee shops). Sure, the iBook bogs down occasionally when I'm running Adobe CS and Studio MX together, but other than that, I'm more of a bottleneck than my computers are. And I say this while typing on my Dual 2GHz PowerMac G5 at work. For most things, my iMac at home feels just as fast as the G5.
Especially if you're coming off a 400MHz PowerMac G4 (which, coincidentally, was my previous computer).