I have started using FBackup - and it seems to work really well.
Basically, I have my music collection twice - once on my portable hard-drive, and again on my HTPC. The backup is set to backup from the portable drive to the HTPC (because I put all new music on my hard drive).
However, 95% of my music is already on my HTPC (I used to manually add new music) - the backup still insists on backing everything up, overwriting the files. It's taking forever! I know that once it's done, it will only backup what's changed, but this is still a problem.
Any advice would be great,