Related link: http://jakarta.apache.org/commons/scxml
Stumbled upon an interesting utility last month: Commons SCXML promises to be an interesting tool for anyone who has to work with state machines. This component is based on a W3C recommendation form the Voice Working Group, and much of the initiall work has been completed by Rahul Akolkar.
Broken link
Commons SCXML is still in the "sandbox", the correct URL is http://jakarta.apache.org/commons/sandbox/scxml/