Right. Very neat. I will have to look into it. I do have a GV number, but I've never used it.
Google doesn't yet have Voice in Canada (don't allow a GV creation from within Canada but can use an already-existing one here), but before I moved here, I ported my AT&T cell number to Voice, then forwarded it to a US Magic Jack # which also forwards to a Canadian # so family/friends in the U.S. can indirectly call my Canadian phone without the extra costs. I also sometimes get bored using the phone and just pop on the headset and use the browser GT (within Gmail) which uses my ported AT&T GV # and Google contact list. Also text people in the states and Canada with my Gmail (for free) using either the browser Gmail or using an e-mail client. It's a pretty nifty service.

I have a friend back in California who's Canadian, he and his wife are moving back to Canada at the end of next year, and he will go through the same porting thing + use in Canada that I did.