It's fun, you can work with or without a partner, and only a small amount of money is needed for apparatus. Most importantly, it will draw all those television addicted two year olds outside where they can get exercise.
Does a two year old screaming in glee, and clapping her hands count as exercise for her? Or just for the adult who should have known better, providing the entertainment.
The back story...
I had a small party yesterday, 30 people. two people under the age of 5. I, knowing nothing about children except that if you purchase them fudge, don't be there when their Mother sees them. - I also hear that until about the age of 3 they leak, but I have no experience in this phenomena. I purchased some large balls they could throw, some bubble stuff they could make bubbles with, or dump on the floor. Option two being the most popular with the two year old. I also bought some blow up punching bags.