I've actually been a test subject for sunscreen here in Australia. It involved having sunscreen put on different parts of your body, hopping into a Jacuzzi for an hour or so, then being zapped with UV on both sunscreened and clear skin.

Easiest hundred bucks I ever made, gotta say.

You get paid for an hour in the jacuzzi? Sign me up ;)

How did they measure the effectiveness of the sunscreen and any side effects on your skin?