So right now I'm in the market for an External Hard Drive because I only have a 100GB HDD and I need a place to backup my Mac, place my .cr2 (RAW) photos, and run a few other Operating Systems via Parallels 6. I wouldn't see there being any problems with Backing Up and placing my photos using a USB Ext. HDD but would Parallels run slower if I put them on a USB 2.0? or should I look for a FireWire 400 Ext. HDD instead? The only problem with the latter is that it seem they are a bit more expensive than just a USB 2.0 Hard Drive.