Joe Green, NationBuilder co-founder

In the summer of 2004, Joe Green, then 21, lived in a trailer with a 70-year old roommate in the 120-degree Arizona desert, while his college friends holed up in a house in Silicon Valley were building a website called TheFacebook.

Green led the grassroots campaign for John Kerry, the 2004 Democratic presidential nominee, for four months in Lake Havasu City, Arizona, mobilising local residents to knock on their neighbours’ doors and win votes for Kerry.

Today he’s become the president of NationBuilder, a start-up company that builds software to make jobs like the one he toiled at during that hot summer easier. Read more