The Brighton Coding Dojo is a regular event set up to let everyone experiment with coding in a non-competitive, collaborative, fun environment. Everyone is welcome, from beginner to Jedi master. The dojo runs approximately twice a month in Brighton and is well established.
You can find out more at the dojo wiki which has details of previous and forthcoming sessions that you could attend. Also, you can sign up to the Brighton Coding Dojo group mailing list to get involved and find out more about the fortnightly sessions: http://groups.google.com/group/kilju/.
The rules of the Dojo are quite simple. The meeting room has one computer attached to a projector. Two programmers are selected to address the challenge of the week, one acting as the driver and one the navigator. They must speak continually about how they are solving the problem, so that the entire group follows what is being done. If the group fails to understand then the pair must pause to explain. One half of the pair is swapped out every five minutes. The language to be used and the problem to be solved vary from session to session.
The Brighton Coding Dojo was directly inspired by Laurent Bossavit and Emmanuel Gaillot, who set up the French Coding Dojo, and also by the offshoot Finnish Coding Dojo in Helsinki.