I backup everything in the Members directory, all the variable files, and all the Forum files every 2-3 days. Even though I have dial-up, it never takes more than 45 minutes. I also keep the latest backups of all of my sites' files in two different locations (one for development and testing, and one for "safe-keeping") on my PC. About once a month I backup everything on CD-RW just in case something should happen to my hard drive.
