Vonage (NYSE: VG) is off to the races. Shares of the rocky dot-com
telco traded as much as 23% higher today after it introduced its first
Vonage Mobile application, which will work with Research In Motion's
(Nasdaq: RIMM) BlackBerry and Apple's (Nasdaq: AAPL) iPhone and iPod
touch devices.

The free app offers prepaid access to discounted international phone
calls. Unlike eBay's (Nasdaq: EBAY) Skype and other Web-based
telephony apps, Vonage Mobile isn't restricted to Wi-Fi access.
BlackBerry and iPhone users can make their cheap calls over their
wireless carrier's network.

This is a huge concession, especially for AT&T (NYSE: T), which has
been historically stingy with its iPhone contract exclusivity.
Everything from tethering to Google (Nasdaq: GOOG) Voice has hit a
brick wall on the iPhone, but now Vonage squeaks through with a way to
let people call overseas for a discount ?

Vonage has been here before. The stock opened 44% higher last month,
after announcing the approval of its App Store application. The
company quickly gave a lot of that gain back, though, when it failed
to elaborate on what its app would do.

This morning's news is a surprise. Marked-down international calling
may not appeal to many iPhone and BlackBerry owners, but this is just
the first of Vonage's mobile applications. Future apps could possibly
turn to domestic calling or provide enhanced features for existing
Vonage customers.