18. Daniel Ek
Daniel Ek
Founder and CEO, Spotify
Age: 28
Industry: Music

If you've suddenly learned your colleague listens to Avril Lavigne, you have Ek to thank. The Swedish brainiac first launched Spotify, which allows you to stream music on your desktop (and, for a small fee, on mobile devices) in 2008 in Europe. It finally made it to the U.S. in July, opening with a bang -- and with a close Facebook partnership that aims to make streaming social. "Our dream is to make all the world's music available instantly to everyone." That's a tall order, but already Spotify enjoys a billion- dollar valuation.

Sandman: Ek spent his last vacation doing archery and driving dune buggies in Dubai.

Last updated October 25 2011: 5:11 PM ET
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