Backups?

[ciphergoth]

babysimon reacted with horror when I told him at the weekend that we still hadn't sorted backups out, and pressed a spare 250GB USB external drive into my hands.

What's everyone's favourite way of doing backups? We have a Windows and a Linux laptop to back up, both are switched on at unpredictable times. I just had a go at making brad's "brackup" go, but despite the great attraction of GPG-encrypted backups, it doesn't seem to be ready for prime time yet - the documentation isn't there yet, and it creates zillions of tiny encrypted files. I am resisting the temptation to write my own Python-based alternative. What do you use?

Update: I since found this rather nice solution.