If you haven't heard of Mozy, it's a free online backup system. I just recently started using it, and the service seems pretty good, although I haven't tried restoring yet! Anyway, you get 2 GBs of free space - well, not exactly free, but close enough. They reserve the right to email you advertisements from time to time (most likely 1-2 times per week), but I can handle that for a free online backup.

Combine this with Foldershare, my new favorite utility, and I can create one folder that gets backed up to Mozy's servers, and gets synched to all of my machines. Yeah, I think I'm pretty safe in the event of a crash...