Spent a couple of hours at the Museum of Mathematics in NYC today. Very hands on. And judging from the noise level in the place I would say a big success with the youngsters. Fun that someone thought to create such a museum and that parents take their kids there. The adults were equally fascinated by the variety of puzzles and experiments around.
Two details that made me smile were the door knob shaped like pi and the pizza pi slicer (complete with directions on how to calculate the pie's circumference and area). Now that's what I call having your pi and eating it too ;-))