to follow up…
I ordered a hard drive today, for the photo back-up thing. I went with a 500 gig external firewire 400 drive.
It also has USB 2, though I don’t intend on using it. When you’re dealing with long, large transfers of data, firewire easily outpaces USB 2, regardless of their specs. I didn’t go the SATA route because my main computer is a MacBook which doesn’t have an expansion slot for the appropriate card needed to connect to the drives.
I went with 500 gigs, because while still being obscenely large, it was a bit more stable than the 1 TB drives. Most reviews on the larger drives make them still sound a bit flakey, which is reasonable considering how new they still are. Even so, I’d guess as a strictly photo-archive, 500 gigs will hopefully last me another year or 2. I calculated that the largest my photo collection could currently be is 140 gigs, but I think realistically it’s gonna be somewhere between 20 and 40, not counting thumbnails and crap.
I picked up a reasonably-well-reviewed drive from for $120 including shipping.