Al Linke's tiny breathalyzer is stored in an Altoids box, and the results can be sent to his Android phone. The key component is the IOIO board, which enables the Android to receive data from eternal sensors.
Interesting little app, although I wonder if the people who would actually need it, would actually use it.
The question I have is about it's accuracy and repeatability. It doesn't look like it actually reports a number just one of 3 ranges. This is probably a good thing so we don't have people splitting hairs. But if the limits aren't quite calibrated correctly I can see a liablity issue (even if its free) if someone is busted for DUI and this thing didn't tell them. Yes, I know that that is not the purpose of it or how it is SUPPOSED to be used, but I also know that those who might be needing this on a regular basis won't care.