I am taking a class in a lab of macs, and will be forced to use imovie and final cut express. I want to be able to work at home on my pc (premiere), work in the mac lab at school, and will be using avid at a later date. This is why I need the portable harddrive. My question is which one if any does avid prefer? Where's the best place to get it? Any advice?

i can tell you this much, my bigger concern would be compatibility between OS's. Make sure you format the drive as FAT32 using the pc first, not NTFS (macs cant read it). Then go from there. You should also do your best to make sure that you keep your files in formats that are compatible between OS's (like you wouldn't want to be using any SD2 audio files or the like) and keep file names short for the mac side of it. My only other recommendation is get a 7200 rpm drive, thats a biggie too.