Yesterday I took part in the "Early Life Study" sponsored by the National Institutes of Health. The study looks at how your socioeconomic situation in childhood affects your health and well-being as an adult. I did a bunch of computer tasks, answered some questionnaires, got my blood drawn and my blood pressure taken. The thing took 3 hours, and I earned $100.

Over the next three days, I have to collect my spit four times a day. After I send those in, I get another $25.