If you have been a computer user for a while, you would probably have experienced the agony of losing your precious files due to hard disk failure or corruption. The answer is of course to make regular backups to another storage medium, probably somewhere offsite.
Recently, I signed up with the service from Mozy.com which gives you 2GB of free online storage. This space can be used to backup and store your computer files. Mozy claims that the storage is secure and encrypted but I can never completely trust this. So, what I did was to use an AES encryption program to encrypt my files before uploading them to Mozy. So far it has worked quite well.
If you should decide to sign up, you can use the referral code 4NG3X3 or this link to get an additional 256MB, for a total of 2.25GB. (Disclosure: I will also get 256MB.)
EDIT 2006-08-01: A free computer backup program with strong encryption is Cobian Backup.