[Daniel] wrote up a quick tutorial on interfacing with the MQ-3, or better known Breathalyzer from SparkFun with Arduino. While we would have used perhaps an op-amp/comparator based system and kept it in a much smaller package, the idea was so quick and simple and enjoyable we hoped an article might keep some hackers from drinking and driving.
[Thanks CletustheYokel for pointing out our silly category mistake.]