A number of sites offer the ability to backup your data for free (up to a certain amt then it’s $$$).
The best program I have used by far is DropBox. You get 2GB free and it syncs all your files with any computer you want (PC, MAC, Linux.. even the iphone and ipad!). It also keeps version history which can come in really handy if an important file (like your password database becomes corrupted).
You can signup for DropBox here