I'm looking to get a data only iphone and am trying to find a good voip app. The problem is I'm in canada so I can't use talkatone and google voice as google voice doesn't work in canada. I'm looking to compare voip apps that have access to canadian call-in numbers so I can get a number in my area (613 area code). For example, skype for iphone would allow me to do this. However I also want the app to be lightweight and not suck down my battery while running in the background. I'm afraid skype might be bloated =/ So which voip app is lightweight, provides decent functionality, doesn't destroy your battery and can get you a canadian number?