While we wait for iPhone apps with push notification feature, Apple has published a [support article](http://support.apple.com/kb/HT3576) explaining the basics about iPhone’s push notification service:
### iPhone OS 3.0: About Apple Push Notification Service
*Last Modified: June 19, 2009*
This article explains the basics about Apple Push Notification Service and where to get additional information.
iPhone, iPod touch, iPhone 3G, iPhone 3G S, iPod touch (2nd generation)
* If the Settings > Notifications menu does not appear on your device, you don’t have an application installed that supports notifications.
* You need to open an application at least once to get any notifications from that app.
* When the iPod touch screen is on and has a Wi-Fi connection, push notifications are received at any time. If the iPod touch screen is asleep, it will check every 15 minutes for a notification.
* If you want to disable notifications from an application, turn off all notifications for that application in Settings > Notifications.
* When you restore a backup to a different iPhone or iPod touch, apps will need to be opened again to get notifications.
Apple Push Notification Service requires iPhone OS 3.0 or later and a connection to the Internet, either via a cellular data network or Wi-Fi, and at least one application that supports notifications.
For additional information, see the [iPhone User Guide](http://www.apple.com/support/country/?dest=manuals), the [iPod touch User Guide](http://www.apple.com/support/country/?dest=manuals), or [www.apple.com/iphone/appstore](http://www.apple.com/iphone/appstore).