Well this thread inspired me to finally buy a dedicated external backup drive.
I just bought a 1Tb Western Digital Elements USB drive for $88 shipped from Dell:
I wasn't real happy with the $30 e-Sata enclosure I bought a couple years ago and I ended up sticking the drive in my PC anyway, which sort of defeated the purpose of having an emergency backup drive that wouldn't get fried if my PC blew up.
This should do nicely though. A ton of storage, simple USB connection (ie, no e-sata problems) and its dirt cheap.