The idea is ingenious because it completely bypasses the need for a technical knowledge of how to create art, and kids are instantaneously attracted to it. This sort of interactive art that anyone can join in without needing skill or large time commitment is precisely what Free Style Arts specializes in. For the past ten years they've been pushing community-based art in Queens and have successfully teemed-up with businesses organizations and the city to make institutions in the area very conscious about creative public engagement. I'll be seeing more of their work next weekend.
The Queens Museum of Art also had a "Mobile Museum" cart filled with art materials that anyone can use for free. The cart is pushed around Flushing Meadows-Corona Park (which is actually larger than Central Park and has some amazing attractions and sculptures) and passerbys are invited to check it out.
There was also a free puppet show. Afterwards, once the kids had gotten all excited about puppets, there was a free puppet-making workshop.