In the world of telephony one of the hottest stories of the day is the long awaited delivery of iPhone SIP client applications. While there have been iPhone SIP apps for some time, it has only been in recent months that they have become widely available and easy enough for most of us to use. It seems strange that with a phone as advanced as the iPhone that something as important as voice over Internet protocol (VoIP) would be slow in coming. But it has. The reason why is because of a strategic decision by Apple to prohibit the use…