Google Voice + Sipgate + PIAF + Orgasmatron == Free home phone service.
Instructions are at nerdvittles . . .
Ya, it’s been spammed all over the web by now–I know. But, I actually set it up and have tested it. The only downsides I have noticed is that call-setup takes more than 15 seconds, I can’t set my outbound caller-id to my “real” number OR use LNP to move my real number over, and there is roughly 500ms of delay (though you probably already have worse on your crappy cellular service and never noticed.)
Of course these are all initial impressions. In a few weeks I will post back on how I really feel, after the new-geek-toy-smell has worn off.