The colmeia group recently installed their Caffeine Viewer project where they hacked their coffee maker to log their "insane coffee consumption" in real-time. Every time a person presses a button on the coffee maker data are logged, but there's a slight twist - the data are available to everyone via the caffeinated API. That's some serious self-surveillance. There are also a few visualizations, but mainly, they invite others to create their own.
How much coffee do you drink every day? More importantly, if you saw how much coffee you drink per year, would you cut back?