#1. Mark Zuckerberg (25 Years Old)

Website: http://www.facebook.com

Why They Matter: Mark is at the top of our list for two HUGE reasons, he is the world’s youngest billionaire and he runs the world’s largest social networking website which is actually the second most visited site in the whole world, not bad for 25 years, is it?

#2. Matt Mullenweg (25 Years Old)

Website: http://wordpress.com

Why They Matter: Matthew Mullenweg is the founder of Wordpress, the software that runs this blog and millions of others out there. Without Matthew, you probably wouldn’t be at this website right now because I wouldn’t as fond with blogging without his genius, easy to use blogging software. He has been offered over $250,000,000 for his company which he turned down.

#3. Pete Cashmore (24 Years Old)

Website: http://mashable.com

Why They Matter: Pete Cashmore makes our list because he runs on of the world’s top blogs which is about all that is new on the web. With over 1,600,000 Twitter followers and 300,000 RSS readers, you know this guy is running something big!

#4 & 5. Aaron Levie and Dylan Smith (23 & 22 Years Old)

Website: http://box.net

Why They Matter: Box.net founded in 2005 was originally launched as a college project to share and store any type of file, and make it accessible from anywhere in the world with an internet connection. The company nearly has 2 million users on the service, and netted a $6 million in venture capital.