Health Tracking Network
The main goals for the Health Tracking Network are to monitor common illnesses and identify the factors related to illness. Volunteers from around the world report their cold and flu symptoms on a regular basis. Participation requires no more than 3-4 minutes a week, and volunteers decide how often to visit the site. Through their participation, volunteers earn money for charity, and also gain access to personal tracking tools for monitoring other aspects of their health, fitness, or anything else of interest. The site has no ads, and participation is free and completely anonymous.