Hi guys, thanks for your comments.
@fubby: unfortunately that script is somewhere lost on an old computer - the project is dated 2007. However, I recall that the code was nothing really complicated.
For the project we used a Figaro sensor that was extremely sensible and accurate. For That's Alcohol project we didn't need to have a precise calibration - the interaction design of the project didn't require it. Anyhow, you can find on the Web different explanations regarding how to calibrate an alcohol sensor. Basically, you just need a glass, water and pure alcohol and some patience. Have fun!
@federico: Of course it is
@all: meanwhile - the project page has moved on another website. Please find it here http://www.tinktank.it/portfolio/contents/exhibition/thats-alcohol/