If you’ve always wanted to play air hockey in real life and couldn’t shrink yourself down enough to stand comfortable on a regulation table, this may be a solution. It is a DIY hoverpuck that uses a motor, propeller, and a puck-shaped case to create a real air hockey experience at full scale.
Don’t want to waste your life building this thing? If you’re a teacher you can pick one up here and use it for physics experiments. I’d suggest actually doing it yourself, though.