Pgbarman does the online backup of our main Postgresql server (2 GB databases) to our backup server. It gives us point in time recovery (PITR) so that we keep every keystroke in case of a crash of our main server. Installation is not the easiest, but functionality is very good!
Barman works great! We were about to roll our own solution in the summer of 2012 and then we found barman and used it instead. We currently use barman to backup about 20 production systems with 100GB+ of data.