15 companies that will change the world

CEO: Ben Heywood (President)
Disruption: An online community where patients discuss and track medical conditions
Disrupted: The health-care industry, medical research

There's plenty of basic data about diseases on the Internet, but there are few central repositories for firsthand accounts about what living with those diseases was like. PatientsLikeMe consolidates such personal accounts and helps patients track their progress. The deep and engaged community has only a few thousand members, but is already a boon to medical researchers; access to such communities of patients is a fast bypass around restrictive privacy rules.