Though the Two and a Half Men actor isn't the first celebrity to express interest in tech, Kutcher may well be one of the most successful celebrities to hit Silicon Valley in years. To wit, he's invested in more than 25 startups like Airbnb, Foursquare, Flipboard, and Path, by way of a venture capital fund called A Grade. Most notably, Kutcher was asked by venture capitalist Marc Andreessen to invest in Skype back in 2009, nearly two years before the service was sold to Microsoft for $8.5 billion.
Great ideas are hard to come by. Putting them to work is even harder. Meet the founders who turned concepts into companies and changed the face of business.
