CRUDdy Buddy is an AIR application I created to generate the code necessary to get started on a Zend_Amf project. It creates all of the PHP necessary, along with ActionScript classes and <mx:RemoteObject> tags you can paste into your Flex or AIR application.

They have a video on Vimeo showing it in action. You'll need the Adobe AIR runtime to be able to use it, but that's a simple and quick install. There are versions for both Mac (using Mac-specific fonts) and Windows/Linux (using Arial). You can download a PDF of the documentation here.