I have been playing around with the free pbx pc software from 3cx. Even added a Obi110 box so 3cx can answer and/or dial my plain old telephone and also my google voice.
I was using the 3cx app on my rezound so I can answer my plain old telephone when away from home.
Well, it turns out that the HTC ICS leak includes a VoIP internet phone which seems to work well. It works more in the background and seems more integrated into the rezound than the 3cx app.