Voice-over-IP service provider Vonage has released its new Vonage Mobile applications for the iPhone and iPod touch. Vonage Mobile allows users to place low-cost international calls over Wi-Fi or, in the case of the iPhone version, over a cellular connection. Features include the ability to dial using saved contacts, the ability to use the iPhone’s existing phone number for caller ID, real-time balance updates, and more. The Vonage Mobile applications…