Carbonite Backup
Last week my notebook's hard drive failed. All the data was lost. A couple of months before, I've subscribed to an online backup service,
Carbonite. I was able to recover all the data I cared for, so that's why I'm recommending it.
Basically, you pay $5/month regardless the space you use.You select the folders you want to back up, and it backs them up silently when you connect to the internet. You can suspend the backup process if you need to use your bandwidth for something else.
Use this link to download a free 15-day trial subscription to Carbonite, and get an extra free month of service when you buy (and 3 months free for myself;) :
http://www.carbonite.com/raf/signup.aspx?RAFUserUID=2508&a=0