A humble, everyday, plastic cup. How can you make it jump?

Creep up behind it and shout ‘BOO!’? Perhaps. But Gareth has another plan. He’s going to…

…blow at it. Eh?

If you have a little stack of cups, and you blow hard into the gaps between them, you can make the top one pop out of the stack, like this. Which, by itself, is fairly dull.

However, if you have a large stack of cups like this, and an air jet from a compressor:

…you can make the cups really jump!

There they go!

Pointless. But fun, eh? You can try this for yourself, using a can of compressed air from a photography shop. Be warned, though – you need the larger cans. The smaller ones are just too weedy to do the job, and even with the big ones it takes a bit of fiddling.