What is LinkedIn:
Website: www.linkedin.com
LinkedIn is a social networking site specifically for professionals and businesses. You can create a profile describing your expertise and work experience, add "friends" (called "connections" in LinkedIn jargon), and even give public recommendations for your colleagues. LinkedIn is, by far, the largest social network for professionals. Some people are already using LinkedIn as their "resume" by making their profiles public. For example, here is my LinkedIn profile.