What interface do the dual USB 2001 rev B g3 iBooks support? Can someone please recommend a good 5400 rpm HD for replacement of my current 4200 rpm drive? I'm looking for around 20-30 gigs of space. Thanks. Edit: Nevermind. I called seagate tech support and they have a 20 gig 5400 rpm drive ST92011A, ATA-6 interface that's backwards compatible with the ATA-5 I currently have. Newegg lists the drive for $65.