I've been playing with a new site for corporate data that Business Week just put up online Wednesday. There are lots of sites for company data but I haven't seen one that tracks relationships among business people in addition to providing data. The Company Insight Center (yes, it could use a better branded name) does that as well as show all the Business Week articles recently written about the person and the company. Check out the Apple page.
One of the things I particularly like is the info on 322,000 private companies from around the world. That's hard to come by.
But my favorite part is the Six Degrees of Separation information that tracks board members across public, private and nonprofit institutions. It shows the connections between people and organizations. So if you're checking out the chief operating officer of, say Apple, you can see that he has deep ties to folks at Nike. Which is probably a good thing since Apple and Nike are very into design and the consumer experience.