This has been Inverted for a while now but has never been fully transparent so since I figured it out on ICS, I figured I'd do the Gb version also since a lot of phones don't have and won't see ICS for a while... This has the video chat and it worked for me but just like any apk, some phones just won't play nice.. Enjoy!
Pretty simple, just download this http://bit.ly/GBTalk13Transparent and flash it in recovery or rom manager...
For anyone wanting to know how to get that chat screen transparent:
We edit line 2834 in ChatView$MessageItem.smali to const v5, -0x100 for a black bg. So I looked up the public ID for Transparent in framework and it's 0x0106000d so I made line 2834 look like this instead const v5, 0x106000d so now instead of pulling an rgb from smali, it's pulling an ID from framework.. Then a few xml edits in values and layouts to complete it and a few png images... Boom! Gotta Transparent Gtalk.... Enjoy!