The London Java Community
Email from Barry Cranford states that the London Java Community (founded in 2007) has now reached over 750 members. They run their meetings using meetup.com and they maintain a blog.
"...Having been founded in November 2007, after twelve months we hit 250 members, I had hoped we could grow to 750 by the end of the year so it’s superb that we have done it 2 months early! Thanks to all our sponsors, presenters & members for your continued support of our community, I hope we can keep giving you the presentations, events, support and advice you are looking for. You can find us at: http://www.meetup.com/Londonjavacommunity -- Barry Cranford