Gonzalo Ayuso has a new post today showing how he set up Android push notifications to a Phonegap-based application with PHP.

Last days I’ve been working within a Phonegap project for Android devices using Push Notifications. The idea is simple. We need to use the Push Notification Plugin for Android. First we need to register the Google Cloud Messaging for Android service at Google’s console, and then we can send Push notifications to our Android device.

He includes the steps you'll need to push the notification and the library to make the cURL connection out to the Google messaging platform. He's posted the full code out to github.