Methods and systems are provided to connect telephone calls, such as international phone calls, using data and telephone networks of a mobile communication device such as a cellular phone. A routing engine determines from the available communications interfaces (e.g., a cellular voice interface, a cellular data interface, and non-cellular data interfaces such as WiFi and WiMax) and from a set of user preferences what type of routing should be used for an outbound call. For example, call routing can be performed using VoIP calls over non-cellular networks, VoIP calls over cellular data networks, voice calls using substitute number termination, voice calls using calling card routing, voice calls using bridge-based calling and conventional cellular voice calls.