I made a human powered water still for a project at uni, someone peddles on a bike which turns a gold trolley motor via a gearing system, the power is then used to run a heating element which boils water which is then distilled. I have to give a presentation of the project in a couple of weeks, I don't want to demonstrate the distillation part of the project because it's not interesting to look at. I want to just run some things off the bike to demonstrate that side of things and then talk about the still. Something which I could use as part of the presentation would be best, like a projector ot something, but any cool things would be fun to liven the presentation up.