I recently got a shiny new iPhone, and its sold me on the idea of a Mac. My iguana decided to ruin my laptop today, so I need a replacement. It was the excuse I was looking for, I guess. I'm not sold on a laptop or desktop, either would be fine. I'm on a bit of a budget. Around $500 or so. My current computer has an AMD chip, 40gig HD, a DVD burner, and 1.25 gigs of ram. I'm looking for something similar. What would be a good model to look for? I'm assuming used is the best option to stay in budget. G3? G4? iMac, MacBook, no clue what any of this means.