I've been struggling with the whole backup issue for some time. Everything I've seen proposed has weaknesses; the biggest of which is usually me getting round to it!
- offsite backup over the web- it was too painful on my internet connection and was costing quite a bit in data transfer.
- I've used the CD and DVD rewriter approach, but frankly it's a pain.
- I backup photos to picassa web albums, and to the ipod too, but that leaves plenty of other stuff still reliant on my diligence.
- The best is the work stuff, which I backup by synchronising that part of the hard disc with the work server; but this is still manual, a bit slow, and can't be done over the web.
Crashplan's approach, which I intend to try soon, is that you first do a backup onto a USB hard disk. You then take this disc to a friend or relatives house and connect it to their PC- meantime your friend's done the same thing in reverse.
Once both PC's are running the proprietory crashplan software and connected to each other via the web, incremental updates happen on both backups on a continuous basis.
If the worst happens and you have to restore, you can just go fetch the USB disc and, so the theory goes, you've got a complete mirror.
I'll post when I've tried the practice and seen how it compared to the theory!