Hi All: I've been a long time PC user and I want to get an iMac for my next computer (24", 3.06GHz, 4GB RAM, 1TB Drive). I got a MacBook Pro from work and I instantly loved it! Sorry if I'm asking silly questions, but Macs are new for me. 1. Can I leave the iMac on all the time? That's what I do with my PCs now; just leave them running. Will this cause any problems down the road? 2. More than likely I'm going to wait until Macworld 2009 is over before buying anything, but I work for a University and I can get some really great deals now. Should I just bite the bullet, chance it, and buy now? 3. Reading through some posts, I have noticed people complaining about the iMac screen and having to return them because of dead pixels and color issues. What things should I look for to make certain that I have a "good" screen? Thanks in advance!