Google Contacts in a Thunderbird tab

For those who want to open Gogle Contacts in a tab: install Google Calendar Tab. Then go to TB menu and open Tools/Extensions and click on GCT preferences. You'll find a dialog box. Click on "Google Apps for your Domain". Then edit it into "https://www.google.com/contacts". You'll have Google Contacts opened in a new tab. Remark: I have gContactSync installed, I did not verify if that works without gCS.