I’ll probably never use it, but Google Voice for iPhone may have been one of the most anticipated iPhone apps ever. Apple has finally approved the native iOS app to run on iPhones in the United States.

You can download it for free in iTunes.

The features include:

Cheap rates for international callsFree text messaging to U.S. numbersVoicemail transcriptionDisplay your Google Voice number as caller ID when making callsPush notifications to alert you instantly when you receive a new voicemail or text messageMost of calls will be placed via Direct Access Numbers, making them connect just as quickly as regular phone callsCall contacts from your iPhone Address Book or enter new numbers on the dialpad.

Forum discussion at Google Mobile Help and Google Blogoscoped Forums.