I've been watching Star Trek lately, and they are always drinking Synthehol. According to Data's short description: "The intoxicating effects can be easily dismissed"
Anyways I think this is a great idea. Imagine being able to go to the bar, tie on a nice buzz, and when its time to go home you somehow hit the kill switch in your brain, and you can drive safely home.
I suppose we'll probably see this when we get the flying cars. Come on you boffins, its 2009!