Damn. Give up coffee? I wish I had the discipline this guy has. He quit coffee using data he gathered on his own behavior.
I found this specific article after reading an extensive article in the NY Times called the "Data Driven Life." I dig the concept.
I'm an allergy sufferer. I can sneeze 20-25 times in a row if I don't control it with nettles. Each time I saw a doctor to find relief I was prescribed one of the many drugs - Claritin, Flonase, etc. Beside the side effects of headache, nasal dryness, and dizzy/drowsiness, I was curious to find out what I was so allergic to - what made me sneeze. I always considered an application that would randomly ping me to ask how I felt. I'd note my findings and compare it to location (work or home) and pollen counts in my city.
Never got to the level of notation described in the article. Gotta sneeze. Ah... ah.... bye...