"It’s a mistake to think of LinkedIn as a giant job board and your profile as just another resume. The power of any social networking tool is in the networking."
The article covers the various reasons to be on LinkedIn to help grow your career. Including building a network for later when you need it, reading the news around your industry and numerous areas in between.
One of my partners is a professor and he recommends to every student they need to be on LinkedIn, not when they graduate, today. It is also one of the top branding sites for your career growth, whether you are in college or are already numerous years down the road and should not be ingnored.