If you've ever doubted how intoxicated you really are by the end of an evening, this hand-blown glass tumbler with a ball maze in the base can keep tabs on your dexterity as you down drink after drink.
The maze itself isn't that complicated. After a couple of cocktails, you should have no trouble getting the balls to their destination. But as the evening wears on, you might lose your ability to solve this simple challenge — or, if you try it, you might end up pouring tequila all over your chest.
It's certainly not as scientifically accurate as a breathalyser, but if it successfully convinces you that you're too blitzed to solve the maze that is the drive home, then it's totally worth $US20 when it goes on sale later this year.