I recently joined one here in my area. I live in a pretty large area, so I had several to pick from. The first one I didn't care for too much - most of the twins were over 20 and out of their houses, and I was really looking for a younger crowd. I really like the current one which I joined their stork club. They have a massive consignment sale, their meetings are at an inconvenient time but not any worse than the other club, they serve us dinner, and there is a lecture, but the last one was on positive parenting and I enjoyed it.
I'm also a twin myself, and I have fond memories of club gatherings from the child perspective, so I really wanted to find something similar for these wee babes.