On the SitePoint PHP blog there's a new tutorial posted (by Lukas White) about connecting PHP with Growl notifications using the Prowl iOS-based tool.
Suppose, however, you want a quick and easy way to send messages to yourself or a select group of people without having to register an application with Apple and play around with various certificates and processes. You might be interested in learning about Prowl. [...] You can purchase a copy for your phone and "hook it up" to all sorts of services and applications - and perhaps most intriguingly, use its API to send messages from your own applications. That's what we'll look at in this article.
He helps you get all the pieces you'll need to get the example working - signing up for Prowl, downloading the iOS application and grabbing the API library from Github. He includes example code to set the provider key, create a filter for sending the message and pushing the request out to the API. He also includes an interesting example of a logging integration with Prowl and a ZendLog. He creates a custom log writer you can drop into your code.