PQuery is a set of helper classes for JQuery JavaScript library.This library allows you to easily integrate AJAX , Effects and other JQuery functionality into your PHP scripts.IT has a small foot print and is compatible with PHP4 and PHP5.

They've also included an example of the code to show how simple it can be as well as links to download the library, check out some other demos (including an Ajax demo, two Effects demos, and two simple applications - a chat and to-do list), as well as pointing you to the complete documentation for the project.