I'm looking at buying a 3.06GHz, 24" iMac. Reading the forums here, I've learned that it's a much better deal to upgrade RAM after purchase, rather than have Apple do it. When I googled how to do it, though, I found an Apple support page that seemed to say that the 24" can handle 3GB at most. So, two questions: first, did I read that correctly? Even if I put 4 GB in, the iMac can only use 3GB? Second, if that's the case, should I just buy one 2GB stick? Thanks!