Started as a way to tutor his cousin, Sal Khan has developed an extensive library of online lessons in subjects ranging from Math to Science to History. While most online learning approaches are stuck in either the lecture format or the impersonal slide delivery (or worse, just a list of readings), Sal found a way to personalize the learning experience.

Sal Khan at Gel 2010 from Gel Conference on Vimeo.

His approach is simple, yet effective and inspiring.