[From Hans] iPhone Developers Get Push Notification API according to the Gizmodo website which is good work because it will enable the likes of notifications when someone sends you an instant message on AIM etc. "pple's just seeded the push notification API to developers through the second beta release of the iPhone 2.1 firmware. What this means to you is that developers can now tailor their apps to receive notifications in the background while it's not running, something supremely useful for apps like AIM, and to a lesser extent, Twitter and other social networking apps."
More after the Gizmodo.