It is ironic that despite the number of data backup utilities available, both commercially and as open source, the percentage of people doing back-ups regularly is not even beyond 50%! One can only do so much to educate people of the importance of backing up ones' data.
[image flickr:topato]
Here's a Python-based back-up utility, pybackpack, that allows you to back-up data locally or on external media.
Now, I do think that you no longer have a reason NOT to back-up regularly. Oops, Time Machine kicks in – to do my hourly backup. :)