Not everyone has the cash to fork over for one of the many fancy portable breathalyzers now on the market. Enter the urine-analyzer ("urinalyzer"?): a new device which measures your BAC when you hit the restroom after a drink or ten. The device is the brainchild of marketing agency DDB and Zouk, a popular night club in Singapore, and is cleverly designed to stop drunk drivers from leaving the club. This is how it works: First, night-clubbers hand off their car keys in exchange for a special RFID card from the valet. Then when they go to take a whizz, the card will pair with the urine analyzer, which provides instant feedback on a screen above each urinal. But if someone who's gone above-limit won't heed the first warning, the RFID card warns the valet, who will then offer to call the clubber a cab or pitch them the club's own drive-home service. There's room for this tech to grow—as there's only a urinal version, so it's currently men-only—but the system has already successfully tagged 573 people over the legal limit in two weeks. Unfortunately, only 342 of those detected opted to take a cab or the drive-home service, but those numbers could be improved with police involvement. Watch DDB's own tour of the system below: