Received a comment from Duccio about the release of a push notification server library for the iPhone, iPad and iPhone touch for which the code has recently been posted.
Here are some of the features:
Autoload system, explicitly include only Autoload.php and all classes are loaded on-demand.
Message class, to build a notification payload.
Push class, to push one or more messages to Apple Push Notification service.
Feedback class, to query the Apple Feedback service to get the list of broken device tokens.
Push Server class, to create a Push Server with one or more (forked) processes reading from a common message queue.
Log class/interface, to log to standard output or for custom logging purpose.
The APNS-PHP project can be found here and it looks like it should be a great time saver.