Forget about Google Voice offering a native app for the iPhone, today Vonage is releasing their own app for the iPhone and BlackBerry.  The application is free and allows low-cost international calls over Wi-Fi and cellular voice networks.  The Vonage application for the iPhone makes calls over Wi-Fi when in range of a hotspot, but it can also route calls over the voice network, said Michael Tempora, senior vice president of products at Vonage. In the latter case, it works similarly to the Google application. The Vonage app for BlackBerrys works only over the voice network; the iPod Touch version works over Wi-Fi.

[Via NYTimes]