A simple toy that can be made for a few dollars, didn't come from China and will entertain children for hours.
Step 1: Why and How
I was asked to build something like this from my wife. She took our boys to a childrens museum and told me about this exhibit that all the kids loved. From the tiny cell phone camera picture she showed me I came up with what you see here. The way it works is you fill the base container with water up to the holes in the pipe that has a water fountain pump inside. Turn on the pump and it carries the water to the top and then flows down each ramp until reaching the container and starting over. The fun part for the kids is putting all sorts of different balls and toys on the ramps and watching them roll and float down. I didn't think this would be very entertaining for them but most kids seem to really enjoy it.