The question really is how much do you value your data? A little? A lot? My solution is a dual solution (albeit still waiting for the 2nd part to arrive). Online I have a subscription to CrashPlan (although there are other various services available which will do a similar job). You can get the software which will backup your computer (or selected folders) to another computer with the software installed over the internet (e.g. your parents if there is enough free space). If you pay a subscription you can back up your files encrypted to CrashPlans servers (and I think you can even put in your own encryption key), albeit it can take a few days to do this. You can even get family packs for multiple computers.
The 2nd part for which I am waiting is a networked attached storage - I am getting a Synology product, although again there are other companies making these. The model I am getting will have 2 spare bays for hard disks of your choosing, and then you can run a backup on your computer to these which will keep the discs up to date. You can also use this as a file server, as well as a media server, bittorrent client etc. (see the synology website if you are really interested). You can stuff a couple of 2TB drives in there and even implement some sort of RAID.
So you can then have an onsite and an offsite backup with a NAS and crashplan. The 3rd part of the solution probably is to trim down what you store as I can vouch I have a lot of crap that really doesn't need to be saved. Then do regular backups of the really important bits (for me this is not my itunes folder) to DVD-R.
Overall it comes down to how much is your data worth and how much are you willing to spend?