Until Google decides to wake up and offer/extend Google Voice here, the next best alternative is Dell Voice.
You get a free number and you can pretty much call the rest of Canada for free. The best part for most folks is getting around the silliness that Cellular service providers have here about charging long distance fees as soon as you go a kilometer out of town. Dell Voice lets you call land lines or other mobiles using your data plan.
Hey Google! Will you give Dell some competition already?