The game changers who are remapping the digital landscape.
His search-engine breakthroughs made him a billionaire. His mother's Parkinson's disease inspired his current fascination with gene mapping and prompted more than $50 million in research funding.
The Twitter founder's latest brainchild is Square, a mobile-payment startup managing $2 billion a year in credit-card transactions. It already poses a significant threat to companies like PayPal.
Karp was a mere 20 when he founded Tumblr--now hosting more than 50 million blogs. His latest innovation: a revenue model that allows users to pay for content placement. Will an IPO come soon?
In just two years and with only 13 employees, he transformed Instagram, a photo-sharing app for the iPhone, from an unknown startup to one with 35 million users and a $1 billion purchase price from Facebook.
Cook has capitalized on Steve Jobs's inspired sense of design, building a global manufacturing system so efficient that Apple's stock has soared 50 percent on his watch.
Founder, Khan Academy
Since Khan Academy debuted on YouTube in 2006, the virtual school's 3,200 tutorials have been lauded as revolutionary. Bill Gates, for one, is a big fan. …