One thing I've been looking into doing is using Talkatone or other such app on my tablets and Google voice on my computer to handle voice calls. This way I only need to have one of my devices around rather than how I usually keep my phone and tablet nearby. As mentioned by others, the cost savings would be great. I already don't receive a lot of calls (most of my family contacts through IM or texts). The only thing I would hate is to lose the number I have through my carrier. It's easy to remember, and I'm already used to it. Wait, I can port it over. Nevermind.
