Who: Co-founder, Wikipedia
Everyone knows where to find Wikipedia — just type, oh, I don't know, anything into your preferred search engine — but few are hip to how the online encyclopedia began. In 1996, site co-founder Jimmy Wales started up Bomis, a so-called "guy-oriented" search engine that was once dubbed the "Playboy of the Internet." While Bomis, which at times hosted erotic content, failed to take off, it provided Wales with the money needed to launch Nupedia, the online encyclopaedia that would become Wikipedia in 2001. The user-based, collaborative site now has more than 350 million readers and operates in nearly 280 languages.