With the announcement of gizmo5 getting cancelled I tried this out today. It seems to work very well.... as long as I'm signed into gizmo5's SIP server. Is that how it does the call back always? I have Google Chat defined as my Forwarding Phone only but it seems to always use gizmo5. Can you change this with the Advanced option for The One Ring called Forward? What does that box want in it? However, even normally the N900 Google Talk client doesn't seem to get calls from Google Voice.

Is there another way to get your GV to ring your N900?