One of the forthcoming features from the iPhone 3.0 OS has gone live early, as popular iPhone game, "Tap Tap Revenge", gets push notifications.

US blog Engadget has a hands-on video that shows how the function - in this particular application as a way to challenge friends in-game - looks live.

The iPhone 3.0 software update is due to be available in both the UK and the US from 17 June.

Apple offered developers the version of the SDK with the push notification goodies in it back in April, so there should be more devs than Tapulous supporting such features come the 17th.