Lately, a host of gadgets have been cropping up to help determine when it's time to cut yourself off at the bar, most recently this awesome breathalyzer watch by Kisai. Genius in its portability and discretion, this high-tech wrist piece has a three-color indication system (and 10 sub-levels) to give a general sense of your blood alcohol content (BAC).

Just blow onto a sensor for five seconds and take a look. Green means your BAC is anywhere between 0 and .40% (good to go), yellow is .41-.60% (slow down), and red is anything above .61% (homeboy, you're drunk). Though we wouldn't rely on the watch's accuracy to determing if you're sober enough to drive — and really, you shouldn't drive at all if you've been drinking — it's a useful tool for providing a sense of how your night is panning out. Oh, and it tells time too. Not surprsingly, the watch ($149) has already sold out its initial production run. But good news! A new shipment is available for pre-order.

Kisai’s Breathalyzer Watch is USB rechargeable, with a single charge can last up to a month (that’s a lot of nights out).

Above, a tri-color indication system based on general BAC levels.