Lawrence Lessig is a rock star. If you don't know his name, I'd wager you're still familiar with some of his work. He's been a major force in the ongoing debate over Copyright in the digital age, and he chairs the Creative Commons project.
Here is a pretty visually flat but intellectually riveting PowerPoint lecture from Lessig on the subject of "Corruption," his latest passion. It's about an hour, but it's well worth it.