I'm looking at an external backup HD for my PM. I have a 300 GB internal drive so need a 250~300 GB external drive. Mostly I'm interested in the Seagate or the Maxtor One Touch II as I don't need anything super-duper. My largest concern is it "just working" with the backup software in OS X, so perhaps it is the software -- not the hardware -- that is my primary selling feature. In any case, does anyone have any experience with either of these products or similar ones? Thanks!