Free Idea # 240 - Exercise T-shirt

Produce an exercise T-shirt that, when soaked with sweat,
would reveal the amount of calories burnt off or, perhaps,
the image of a food product with the equivalent calorie
content. If a person works out hard enough - and perspires
sufficiently - they would eventually end up with a shirt full
of images (or numbers). The shirt would boost morale,
encouraging people to exercise for longer periods of time.