I really enjoyed the Dojosec series of monthly meetings that Marcus J Carey put together, and I am sad to see it has gone away. Dojosec was a security meetup in the southern Maryland area. The last Dojosec that had speakers was in November 2009. Some of the videos from various Dojosecs are online, so you can still see some of those great presentations.
Hopefully Dojosec will resurface again sometime in the future.
UPDATE 24 August 2010 – Great news! It looks like Dojosec (and Dojocon) may be returning soon.