Apple has released the new iPhone OS 3.0. One of the exciting new features of iPhone OS 3.0 is Posh Notifications. Push notifications is the ability of an iPhone app to alert you of something even if the app is not running (Just like the Mail App notifies you of new emails.)
The same way, Yahoo Messenger is going to notify you of new IM message as it arrives even if the Yahoo messenger App is not running. This feature is not ready yet but Yahoo Messenger team is working on it and we can expect it really soon.
We’ll keep you posted whenever Yahoo Messenger for iPhone will support Push Notifications. So, stay tunes at iphoneheat.com. For now you can download iPhone OS 3.0 and enjoy the great new features of iPhone OS 3.0.
via [Yahoo Messenger Blog]
Update 1:
Push Doctor is the new best Push Notification Solution: