http://synkron.sourceforge.net/
Main goals of Synkron:
Synchronise multiple folders
Tabs allow you to have more synchronisations running at once
Periodical synchronisations automatically sync your folders in selected intervals
Restore files, which were overwritten during the synchronisation
Add files and folders to black list to make sure they won't be synchronised in the future
Make schedules and backup using multisync
Synkron is Free Software