[Matt Leggett] designed a jacket that is telling you whether you are able to drive or not:

Included in the jacket are an Arduino microprocessor, an alcohol sensor, and a series of LED’s that “provide an elegant solution to the drink driving problem.” A breathalyzer located in the pocket of the jacket, analyses the sample and then lights, that are stitched into the forearm, indicate how drunk you are. The LED lights glow when alcohol is detected and the brighter they glow, the worse you are.

via [Joe.ie]