Today I bought Zack a set of 55 dominoes. We've been alternating between actually playing the game (well, our own made-up version of the game) and stacking them to knock them down.
I escaped for a few minutes to update the web site when Zack decided he wanted to do everything all by himself. I heard him get frustrated as he kept knocking over the dominoes before he was ready. Sad boy.
So I called him into my office and pulled up trusty YouTube and found videos of those guys that stack a gazillion dominoes just for fun and then pray they don't knock down ten thousand of them before the competition, so I could show Zack that grownups goof up, too. And we found this, and I had to share.
This is 10,000 dominoes per second, done by a German team. I have no idea how many dominoes they have there, but I'm just glad I don't have to clean up THAT play room!