Without a doubt, the best reason to join any social networking site is that it lets you make connections with other people. You can use social networking sites to stay up to speed with what your friends are doing. If the social network is popular, you may be able to track down old friends and acquaintances and renew long-forgotten friendships.
You can also use these sites to network professionally. Even if you're happy where you are in your career, you might be able to help someone else out. For instance, one friend might mention on his profile that he needs a carpenter to come to his house. You might know someone who's perfect for the job. All you have to do is send a couple of messages and you've helped two friends out at the same time!
Many social networking sites like MySpace and Facebook make it easy to organize an event and invite your friends. Some sites allow you to group friends using different criteria, including geographic location. So the next time you plan a group trip to the movies, you can send out a notice to your local friends using a social networking service.
Are you an actor, musician or writer? If so, you can use social networking sites to promote your work. Many sites allow users to create special pages for bands or theater companies. You can keep fans informed about everything from your latest single to the next time you'll perform. And social networking sites gives people the opportunity to interact with the artists they admire.
Several social networking sites also act as application platforms. You can find dozens of applications ranging from quizzes to games to restaurant review programs. On a site like Facebook or MySpace, you can challenge your friend to a game of trivia -- even if she's on the other side of the world!
Social networking may even get you out of jail! American graduate student James Karl Buck was in Egypt covering an anti-government protest rally when Egyptian police detained him. Buck sent out a single word over his Twitter feed: Arrested. People following him on Twitter knew that he was in trouble and began to contact U.S. authorities. Before long, Egyptian officials had released Buck [source: Simon].
But it's not all sunshine and roses. There are some drawbacks to social networking too.