Drink driving is obviously dumb, but it can sometimes be difficult to tell what kind of effect a beer has had on your body. Fortunately, Tokyoflash's latest watch straps a breathalyser to your wrist so you can keep your blood alcohol concentration in check.
Blow into the sensor housed on the side of the watch, and the LCD will change colour to reflect your alcohol intake: green is sober, and red is well over the limit. There's even a little on-board game to check your reactions.
Like most Tokyoflash watches, the time is particularly tricky to read -- but maybe that's another mechanism through which you can check your sobriety. For the next 48 hours, the watch will sell for $US100; you can buy it direct from Tokyoflash. [Tokyoflash via Engadget]