Apple Thoughts: Vonage for iPhone/iPod Touch

"Those looking to make cheap international calls via their iPhone may not yet be able to do so using a native Google Voice application, but that hasn't stopped VoIP company Vonage from offering similar capabilities in its new app for iPhone and iPod touch."

If you already use Vonage, this doesn't connect you to your account. This is a pay-as-you-go account. You have to set up a new account, and you get $1.00 USD credit as a reward for your trouble. You also get Twitter as part of the app for posting how exciting your international call making ability is, and then reading about it later. The apps, one for iPhone and one for iPod Touch, are both free.