We blew up a balloon for Kevin's birthday shindig yesterday and the boys have used it for a toy ever since. Unfortunately, this toy has become a hazard for their health, and not because they're trying to shove it down their throats.
The game they play is to toss it up and follow the balloon through the air, hitting it up as it gets low again. Not that original of a game, but they absolutely love it. What they don't love it running smack into things, like walls. And tables. And corners. And...I could go on and on.
My guess is that their peripheral vision is not all that developed at this age.