Yeah, I am glad I got it working, too. SIP, XMPP is a new world for me.
I started off with a GV setup and before I bought the Obi I read about issues with incoming GV calls if Google Chat was open, so I decided to use SIP for incoming calls and GV for outgoing. I also thought it could be fun to use a SIP app on an Android phone where GV would doing an incoming calling using SIP and I can talk without using cell phone minutes.
Most articles talked about setting up with Sipgate and Sipsorcery, but Sipgate is out of phone numbers. So, I found an article that uses IPKall and sip2sip and went that route.
Do you have preferred free providers?