I'm still having a bit of a hard time wrapping my brain around this concept. The G400 is a GPS navigation unit from NDrive that includes a breathalyzer. I guess it is a good way to judge whether or not you should be driving, but my usual rule of thumb is that if I've had enough drinks to warrant the use of a breathalyzer, I should probably hand off the keys regardless. And GPS navigation units are hard enough to figure out as is, just try to do it while slightly inebriated.

From the information at hand, it seems that it requires you to blow into the device every time it is fired up, which could be a major inconvenience for the other 95 percent of the time when you are driving to work, school or to run errands and not driving home from the bar. This device will be available soon for $300, but seems to only be sold in Portugal, at least for now. [Navigadget]