A little strapped for cash? If you're willing to take new or experimental drugs to test potential side effects, you might be in luck. The first round of clinical drug testing, Phase I trials, are done on healthy volunteers to ensure dosages are correct and the drug is safe. Anyone can participate, so long as you aren't sick and are in decent shape. And at the end, you get paid.

Drug trials are a good way to make a quick buck. But for some people, participating in trials is basically their job. These so-called professional guinea pigs go from one to another, looking for their next paycheck. Although a huge industry, the entire business has stayed pretty quiet despite the numerous ethical issues surrounding drug testing. From message boards to couchsurfing, we dive into the world of the professional guinea pigs and clinical trials to get a better idea of what's going on. Enjoy!