Bytes of Life

Messina and Evans prefer the term "data junkies," spoken with the self-effacing self-awareness that comes from months of meticulous self-study.

Self-trackers like Messina and Evans could spend hours online, charting, analyzing, tracking. Life as a series of pure, distilled data points, up for interpretation.

It's not about tracking what you do, they say. It's about learning who you are.

Keeping Track

Self-disclosure has been redefined online. In Web 2.0, it's led to blogs and Tweets, Facebook and instant messenger, each developed to help users share the inane minutiae of their lives with others.

But another kind of site has evolved -- a type meant not to broadcast your life to others but to chart it for yourself, on password-protected sites accessible only to the user. A life examined to the point that Socrates himself might say, "Guys, that's enough."

Messina and Evans are at the tip of the information iceberg. The Internet brims with sites that track just about every task that you perform on a given day (eating, sleeping, exercising) as well as the things your body does without direction (pumping blood, producing glucose, gaining weight).

Some of the seemingly goofier sites have practical purposes: RescueTime was meant to increase time-management skills among business types, MyMonthlyCycles was developed for women trying to conceive, and Basecamp helps colleagues complete joint projects remotely. But dedicated trackers can repurpose these sites for their own self-study -- or use them as inspiration for their own, more intricate tools.

In San Diego, statistics student David Horn already belongs to BrightKite, Last.fm and Wakoopa.com, which tracks his Internet usage. He's also experimented with Fitday.com to map food intake and calorie expenditure. It was satisfying for a while, but now he wants something bigger -- something simultaneously broader and more nitpicky -- to fill in the gaps that individual sites don't currently track.

Horn is working with his engineer girlfriend, Lisa Brewster, to develop an all-encompassing life tracker, under the working title of "I Did Stuff."

"I'd like to track the people I talk to," says Brewster, "and how inspired I am six hours later. And definitely location history -- where I am, what time -- "

"Correlated with weather history," interjects Horn. "And allergy data, pollen and mold in the air."

Plus, "Web sites I read and their effect," says Brewster. "If I spend a long time reading a blog, like TechCrunch, but I don't get noticeable output from it."