Martijn Verburg is a Java/JEE and open source advocate who believes in the creative power of technical communities. He is the community lead for the PCGen and Ikasan open source projects and helps run several technical communities in London (under/graduate Developers, CTOs and of course the JUG).
You can also find him tending the bar at the Coderanch (aka Javaranch) or answering questions in the Programmers section of Stack Exchange. Most recently he's been working on "The Well-Grounded Java Developer" with Ben Evans and speaking at a variety of Java and open source conferences.
Currently abiding in London, Martijn tries to keep out of the pubs (especially during the football season), but fails miserably :)