I have a regular backup scheme involving external USB drives as well. I don't use any special programs. I just have two directories under which all my data is contained. So I just connect my backup drive and copy those two directories in their entirety. I find that a single 160MB hard drive will allow me to keep a year's worth of backups. At which point I buy a new HD for next year's backup. This has the advantage of me having an ongoing sequence of backups from the past that I could go back to if I needed to (either for recovery or for reference), and also that I start using a new backup HD long before the drive gets old and at higher risk of failure itself.

I'm also planning on starting to use one of those online backup facilities. I've never been to keen on them, but a friend of mine has been using one and has only good things to say about it. I'm online 24/7 anyway so the fact that I can just load their app and have it keep the off-site backup up-to-date every 10 minutes is a pretty neat thing.

Regards,
Craig Steiner