From the Professional PHP site today, there's an interesting new post about a game the author found (via digg) of "Heroes of Might and Magic" online minigame. What makes it even cooler? It's written in PHP and uses Prototype and Scriptaculous for the interface.
The interface is very drag and drop oriented and it uses Ajax to update game status. The graphics are very good. No flash as far as I can tell.
The game is a bit less overloaded now, but still a bit slow. The interface is wonderfully done, and easy to understand. It's great to see the popular pairing of Ajax and PHP starting to show up in commercial applications, too.