For the 99.9% of the population who will never go into space, seeing what happens in zero gravity can be pretty fascinating.  Educational too!  Last fall the Canadian Space Agency asked students to design a simple science experiment that could be performed in space using objects already on board.  The winners, two 10th grade students from Nova Scotia, had International Space Station Commander Chris Hadfield perform their experiment in space. 

Their experiment "Ring it out" investigated the effects of weightlessness on the reaction of water after being wrung out of a soaked washcloth. This is what happens:

 

Just because it's fun to watch, here's Chris showing us how he washes his hands in space: