Celebrity Tech Investors MC Hammer

Investment: Hammer, whose real name is Stanley Burrell, has invested undisclosed amounts of angel capital in mobile payments provider Square, contact-sharing app developer Bump Technologies, and several other Bay Area start-ups. In 2007, he co-founded DanceJam, a YouTube-like platform for sharing dance videos that was sold to another company in 2009.

Background: Hammer says he's been interested in entrepreneurship and technology from a young age, but recently admitted to Oprah that it usually surprises people to learn that he's a "super geek." Hammer told Billboard.com that he's "interested in companies that can have a global impact on enterprise in general; things that can make your connected life more interesting and easier."

Fun fact: MC Hammer has given talks at both Harvard and Stanford business schools on how companies can leverage social media. He's been known to tweet 30 to 40 times a day.

Number of Twitter followers: 2.2 million (@MC Hammer)

• Up Next: Bono
• Go Back: Kim Kardashian