I have an iPhone 3gs on at&t and I use text free with voice a lot for calling. The only problem is that when using text free voip over 3g the quality isn't very good such as echoing, and not being able to here the person the the other line. When I test my network speed with speedtest.net my ping is constantly around 480 ms. So how is it that when you make calls using the built in cell phone on the iPhone or any cell phone for that matter, its better quality? And how can I make text free voice work better over 3g.