Mozy offers 2GB of free backup. Install it on your computer, select which files are to be backed up and it encrypts then uploads the data to Mozy's servers. Probably unpractical if your on dialup unless your backing up a very small amount.
http://www.mozy.com/Sounds like you may just want to invest in a USB drive, although I suppose emailing it to yourself works just as well

N0ZLD