I'm only three degrees from Kevin Bacon. And I'm three degrees from Hillary Clinton. In fact, I'm only two degrees from Barack Obama. (Sadly, Cal Ripken, Jr. is out of my network.)
How do I know this? Because LinkedIn tells me so.
LinkedIn and other networking services like Facebook, Twitter, StartUp Nation, Qapacity, Classmates.com exist for one reason: to connect people with other people. The reason for the connection and the tone of the introduction may vary depending on the networking site, but the mission is still the same.