Interesting physics presentation ideas?

How about something every-day.

I liked a lectures a prof did for us on cooking an egg - he went through all the thermodynamic stuff on how to get the centre to a certain temperature and stuff.

Bubbles? Interesting shape, sure there is some cool maths behind them to do with surface tension etc and soap bubbles have that spectral refraction stuff. (forgotten so much since uni T___T)

You have an interesting introduction of "And my presentation is about.... cooking an egg" when everyone else has really dry things like "This is an introduction to string theory..." then quoting Wikipedia.