If there is not one already I think we need a UK calendar of events. I don't think there is a lack of enthusiasm this side of the pond (although I've found many UK events are very dry) but we are far less good at publicity and evangelism.
1. Find events
2. Round up an EH.net posse
3. Eat pizza/drink beer
Sounds like a plan

I'll kick off trying increased publicity: I'm signed up for the
Cloud Camp North-East event on July 29th. Whilst not directly security related, security in the cloud seems to be a hot topic at the moment so I'm wanting to get a better understanding of the technology, and hopefully approach the topics from a security perspective.
There are still plenty tickets available and the event is free (and they supply beer & pizza). If any EH-net'ers plan on attending let me know so we can meet up, might be a good starting point for arranging a more security focused get together in the area.
For those in a different part of the world, check the upcoming events as Cloud Camp hold events world wide.