Xstream: http://xstream.codehaus.org/ (not a binding tool, but a nice serialization tool)
“XML data binding” presentation at JavPolis 2004: http://www.javapolis.com/confluence/display/JP04/XML+data+binding
XML Data Binding Resources: http://www.rpbourret.com/xml/XMLDataBinding.htm (listings of most binding frameworks)
Bindmark: https://bindmark.dev.java.net/ (project goal is to provide a comparison of the existing open-source and commercial (when available for free evaluation download) libraries for binding XML data to Java classes. The libraries are evaluated in several areas, including ease of use (the amount of effort needed to invest to the first successful run), the size of the accompanying jar files and the performance. In this project, the main emphasis is put into providing the performance comparisons, both in time and in memory.