Truphone for Android has been updated and it rocks! The main new feature of version 3.0 is calling over WiFi, allowing Android handset owners to make free calls to other Truphone, Google Talk and Skype users. In addition, there’s also the standard ability to make cheap phone calls to mobile and landlines; as well as chat with your buddies across IM networks.
In addition to WiFi calling support, the new version also comes with revamped UI. Unfortunately, the latest Android handsets (with Android 1.5 and above) are not supported at the moment, but Truphone wowed to fix that soon.
The Truphone application remains free and you can grab it from the Android Market.