I may be spending a nice chunk of time in Costa Rica this winter. The catch is that I would work remotely the entire time. Cell and email connectivity are vital. The email part isn't an issue, but I am concerned with the best way to handle phone calls. I will be staying at my friend's house where WiFi is available. From the research I have done, Talkatone may be my best option. It will make use of my Google Voice number (a Chicago number), but it also ties me to locations that only have WiFi. I'm also concerned about the quality of the calls. So I'm looking for another option. I'm a Sprint customer and they're at $1.99 a minute, which is cost prohibitive. Really, what's important: 1) A US based number. 2) Solid cell coverage. 3) Reasonable cost. Any suggestions would be greatly appreciated. Thanks.