MozBackup

Anyone used this for backing up Thunderbird and Firefox?

Yes, have only had to use it once and it worked fine.

I use it to back up my Outlook Express. Works very well but of course every time you add to any folder it is a "new" file so Mozy's incremental backup will backup all my OE folders each time. No problem but it does mean I am backing up over a GB just with OE.