Class.Jabber.PHP is today’s Freshmeat Gem of the Day (fmGoTD):
Class.Jabber.PHP is a class which you can use to connect to the Jabber network. It allows you to easily connect to a server and interact with it. It supports all packet types (message, iq, and presence), is very flexible, and offers both high-level methods (registration, message sending, etc.) and low-level methods (packet sending, etc.).