DrinkSafeTech.com offers a useful product.
The Drink Safe Personal Test kit contains two tests. About the size of a credit card, they incorporate our patented 'Drink Safe' technology to react with a visible color change when they come in contact with a drink spiked with one of the major 'Date Rape' drugs.
They also offer cunning drink coasters with the testing chemistry built in. I'm not sure if I'm more impressed by this clever idea, or more horrified that it's necessary.