I've recently joined up with a few quilting bees. I once thought they were elusive clubs that were difficult to find open and join. But, that's not the case at all. In fact, it's quite easy to join a quilting bee.
The best resource I've found has been this flickr group. It has a thread where you can find bees to join and post that you're interested in joining a bee. For a couple months, I just looked at the thread (when I had time) looking for bees that I could join. I didn't find too many that were still open. They go fast! A couple weeks ago, I decided to post that I was interested in joining a few bees and my inbox was flooded with invitations. Well, maybe not flooded, but I got quite a few. Moral of the story: Don't be afraid to post that you're interested. Don't just watch from the outside.
Here are a few that I've joined:
[3 x 6] Bee: I did the first round this year and signed up for the second.
Wonky Quilt Bee

around the world { a modern bee }
Sew Modern Quilt Bee
Tokyo Subway Map Block Swap - this one isn't really a bee, per se. We're each making one block from this quilt 25 times, sending it out, and receiving back 25 blocks to make a completed quilt.
Each bee is a little different in it's timeline, requirements and block style. I know I'm going to be busy over the next several months, but I'm looking forward to trying out new things and seeing what everyone else does with the same materials. I really love the idea of the finished product being so easy to complete and so small.