Some friends of mine in California have been discussing backup strategies over the past few days. They came across a post by Jeremy Zawodny on using Amazon S3 in addition to his existing backup strategies.
I’m still only using an external hard drive for my backups. I don’t backup my machines regularly enough either. Before Seagate bought them (and before I joined the cult of the Mac), I had a lot of interest in a Mirra Personal Server. At the time it was Windows-only, but now it supports Mac OS X as well. Recently, I started using Deja Vu for backing up the Mac mini. So far, it’s been completely painless.