Working beautifully with Thunderbird 24.2, Skype 6.11 (with Skype credit) on a Win7 PC. This is a fantastic add-on, but I suspect many Skype users are simply not aware of it.
It allows you to store/edit all your phone numbers in your Thunderbird address book and pass them easily to Skype (or other software) for a call (i.e. avoiding duplicating address books).
I'll definitely continue using it. If you use Skype please read the FAQ on the developer website about the option "Replace leading + with:" Searching the web for the phrase above, TBDialOut & Skype should take you there. It is important.
PS Perhaps a bit off-topic, but perhaps useful for some: I use BirdieSync to share one of my Thunderbird address books (i.e contacts with phone numbers) with my Android 4.1.2 phone. From there I can also pass the number to Skype, although the sound quality of Skype on Android doesn't seem to match the PC for some reason.
This review is for a previous version of the add-on (1.7.2).
TBDialOut is much better than the old Add-On for Skype. I am using it for Skype and I will try use it for sipgate (or any other VOIP-provider) through URL dialing with a Yealink phone. Thanks for a great programm.
This review is for a previous version of the add-on (1.6.0).