Wow, this thread makes me feel so...inadequate! DD and DS each have two activities they're doing this spring, and that adds up to only a few hours a week total; DD occasionally asks to add dance or gymnastics, but she also really enjoys being at home after school and not having to go anywhere.

Not helpful to the OP (sorry @ultramarina!), but encouraging me to try pushing our family a little bit. Maybe we'll try adding something and see how it goes. (Of course it would help if they were interested in the *same* activities, but that doesn't seem likely.)