The Rolls Royces of science experiments--relatively low risk and decent payoff--are Phase I drug trials conducted by pharmaceutical companies. "They want to control the environment very carefully so they can isolate the effects of the drug," Grady explains. "You can find studies where the requirement is to come in for two weeks, and the payment is $2,000." Drug trials can also come with perks. While you're hanging out in Pfizer's clinical trials center, for instance, you’ll get arcade games, a pool table, and widescreen TV.

Drug company Phase I trials are the domain of those people who claim to make a living as scientific subjects (check out a Wired feature on them here). There is a system to it: lining up the trials, making sure you have a two-week cleanup period between studies so you're clean, and so on.