Dunn Lewis is a great shop and community garage in the DC area that had created a good base for people to come together to celebrate their love and hobby in riding. They often have weekly, monthly, and annual events--from movies to guest world traveling speakers to swap meets and rides.
Dirt Church is a small group of friends with a private shared garage in DC. They often get together and do fun events. They welcome everyone and these things are usually passed by word of mouth. They are some of the wildest but nicest people I have ever met with a collection of all sorts of motos and mopeds.
These photos were from their first location (Dunn Lewis that is) and they have recently moved to a better one (I have to come visit!) If you're into the culture, I would suggest checking out Dunn Lewis in Washington DC--especially for those of you who are in the Baltimore-Maryland-Northern Virginia area. It doesn't matter what you ride or why you ride either, everyone is incredibly down to Earth.
Here's a little cute video from last summer. I hopped on the back of this lady's Puch to see what it would be like to have a passenger. I generally get to test out short runs on being first passenger for a lot of bikes. I guess it's because I'm petite and I ride (so I won't do anything crazy on the back).