I was really unimpressed with Apple's Time Machine. Did you know it only goes backwards?! Lame. (Humor aside, it's actually quite well engineered.)

Spideroak.com works too. It automatically backups your data to the cloud (securely encrypted!). It synchronizes your data across multiple machines (and multiple OS) and you can access all past versions of your files. It's free if you don't need more than one or two GB. It's the ideal backup tool for researchers that don't generate tons of data and want a simple backup solution.

..and, by the way, there's an automatic 50% discount for anyone with a .edu (or similar) email address. :)

Flux capacitor + 1.21 gigawatts? Delorians are getting hard to find, though.

You technically don't need a delorean, any car with stainless steel shell will work just as fine (paraphrased from Doc).