DroidCon is a gathering of all of the Midwest Builders from Indiana, Michigan, Ohio and Illinois. We share information, look for interesting new ideas, buy and inspect parts, and listen to speeches on various R2-related subjects. While I was there, I bought some hinges to allow my droid to open its "pie panels" - the blue panels on the top of R2's head.
All of DroidCon's participants were friendly and helpful, willing to assist beginners, and even talk to members of the public just stopping by to gawk. Most were also very knowledgeable about the best ways to build an R2, how to keep it running, what was and wasn't possible, and anything else you could possibly want to know when building an R2.
Most people bring their R2s or other droids (such as mouse droids and R9s) to DroidCon. This year doubled the last DroidCon's attendance with over 100 attendees. It also had almost twenty R2-D2s, the most I have ever seen in one place at one time!