Vonage app hits iPhone, BlackBerry, while blocked from mobile data networks

After enduring patent infringement lawsuits from AT&T, Verizon, and Sprint in 2006-2007, Vonage lost its commanding position in Voice over IP telephony (also known as digital voice) to cable companies such as Comcast and Qwest. Today, the company looks poised to make a comeback with its new Vonage Mobile app for iPhone and BlackBerry.

The free application lets subscribers place packet-based calls over Wi-Fi or circuit-based calls over cellular networks. It ends up being similar to the Skype iPhone application in that it will only use VoIP if the mobile device is within range of a Wi-Fi signal. Otherwise, it will make traditional wireless calls over AT&T's GSM network. Furthermore, when connected to a Wi-Fi signal for a VoIP call, and a call comes in through the cellular band, Vonage Mobile reportedly drops the VoIP call.

As Vonage's PR associate Michael Zema said in the company's official Twitter feed today, "The current Vonage Mobile app uses your existing cell phone number to place calls. It's a pay-per-minute application...The Vonage Mobile app uses your existing cell phone number, not your home Vonage number."

Vonage claims this prepaid service can save users as much as half on international calls.

While cable companies have embraced the VoIP phenomenon, telephone companies like Verizon and AT&T have been somewhat more apathetic in pursuing the technology (unless of course, you're talking about in court, where they've pursued it with fervor). Both Verizon's FiOS digital voice and AT&T's U-Verse Voice are only available in select markets, for example.

However, with a service such as Vonage Mobile, users are afforded a tiny bit more freedom when placing costly international voice calls, even if operators continue to block VoIP from their mobile data networks.