The Week in iOS Accessories: Wired up
Forget about reciting the alphabet backwards. The $25 Alcohol Tester for iPhone 5 plugs into your phone; blow into the air hole, and if your blood-alcohol content is too high to drive, the phone will sound an alarm to discourage you from taking the wheel.
http://www.macworld.com/article/2030522/the-week-in-ios-accessories-wired-up.html#tk.rss_all
