I have been working with the dojo Toolkit for a couple of years and one of the things that I had to do was implement a RESTful class handler in PHP to support the ability to implement RESTful services. In particular I wanted to use the dojox.data.JsonRestStore which supported things like filtering, lazy loading, paging and several other advanced features and have implemented all those in my class. It is written for PHP 5.3 or later (since it leverages namespaces) and I am making it available under the BSD license. I also have just recently moved it to GitHub, so you can fork it to your hearts content.
In addition I do have a sort of example application working which combines Dojo and my classes available at kitsonk/examples.
(Also, you should check out the new dojo.store.JsonRest)