The Google Talk client for the BB seems to work fairly well on the 7100.

I'm wondering if T-Mobile charges an SMS for each gTalk IM like they do with their own clients (yahoo, AIM, etc). Does anybody definitively know? It does seem that the client uses the data connection in place of SMS's.

Yes, yes, I did search. Couldn't find anything relevant except for 1 thread that rambled (http://tinyurl.com/h6mgm).

Let's keep it short and sweet now.

Nope. It's data and included in your BlackBerry Data Plan.