Measuring hard things with easy experiments

Here are some links to experiments that allow you to measure impossibly-difficult-sounding things using everyday objects:

Measuring the thickness of a human hair using a laserpointer and a tape measure.

http://www.fysikbasen.dk/English.php?page=Vis&id=87

Measuring the speed of light using chocolate chips and a microwave oven

http://superpositioned.com/articles/2006/03/09/measure-the-speed-of-light-with-chips