BackItUp for Mac

From MacSpark:

Backing up valuable files can be tedious. A million things could happen. You could forget, or even lose the data! We strongly recommend using this application at least once a week, backing up your most important files, like from work, or school, if anything, BackItUp can do the job. BackItUp is a simple utility allowing you to backup files easily and quickly. Although it is a basic application at it's current state, MacSpark will continue to improve it as much as possible, chock full of features, fulfilling our customer demand. This is a great free alternative to many popular CD-burning utilities out there.