There are some desktop backup tools available for Linux, but most of them are not developed anymore. Areca however is under constant development and also provides a user friendly GUI.

Backups and Linux are a twofold thing: if you have hundreds or thousands of computers backups are not a problem at all: Amanda, Bacula, Restore and others are your friends. Also, if you want to create backups on single machines, there are many tools available: rsync, tar, and many, many more.
However, all these solutions are not suitable for the average user.