how can i do push notification in iphone application?

Question

How can i use push notification in my iphone application.can u please help me by given some source or instruction to include my application.

Answer 1

http://developer.apple.com/iphone/library/documentation/Cocoa/Conceptual/Notifications/Introduction/introNotifications.html

Answer 2

I think http://blog.boxedice.com/2009/07/10/how-to-build-an-apple-push-notification-provider-server-tutorial/ is more relevant.