Review for Addressbooks Synchronizer by Lothar Mueller
Rated 4 out of 5 stars
Apart from a few "flaws" this is exactly what you need if you're using TB from more than one PC. Esp. the possibility to use an IMAP folder to store the sync'ed address books is an excellent approach!
This review is for a previous version of the add-on (0.7.0).To create your own collections, you must have a Mozilla Add-ons account.