Alright, so it finally bit me. I didn't buy AppleCare on my iMac G4, and the hard drive is now having problems. Running Disk Utility gives me an error with the Catalog B-Tree, and DiskWarrior stalls due to a hardware problem (I got impatient and cancelled after 1/2 hour). Luckily, I could boot with my PB as a firewire drive, and pull pretty much everything off that wasn't already backed up. But the hard drive still seems problematic, and I don't want to risk more problems, so I figure I'd like to replace the hard drive. So, I have a couple of questions. The first, and most obvious, is - can I replace the drive on my iMac G4? I imagine I can, but it may not be overly simplistic. Has anyone done it before? I've replaced the optical on my PB, and I'm pretty technically inclined, so as long as it's realistically possible, I'll do it. Second is, which drive should I get? This is where I'm a little unclear. I'm pretty sure it's a 3.5" ATA drive I need, but when looking at Other World Computing I see ATA/6, ATA/7, Ultra ATA, Serial ATA, etc. What does all that mean? Right now I've got an 80GB Hitachi drive, and this seems like a nice opportunity to bump it to something like 250GB or so, since they're really fairly inexpensive. I'll probably run DiskWarrior overnight just to let it run and see if it gets past the error, but I'll still want to replace the drive, so any advice would be most appreciated. Thanks!