It seems like there is a new social media tool popping up everyday. You may have experienced someone inviting you to join a new social network or a person in your office suggesting what social media tool you 'must use!' To avoid a meatball sundae, the first thing you need to think about is, what is the goal you are trying to achieve with social media? Forrester has a great framework for thinking about the different uses for social media. They are: listening, talking, energizing, helping and embracing. I would recommend that everyone at a minimum, listen. Listen to what your customers are saying about your brand and what tools they are using to say it.
There are several tools that can help you listen. Instead of visiting the 1,000's of social media sites, you can use a free aggregator such as Social Mention that monitors conversations on 80+ social media properties such as Twitter, Facebook, FriendFeed, YouTube, Digg, Google etc. In addition to listening to what people are saying about your brand, also listen what they are saying about your competition. It is not sneaky, but smart!
After you have monitored the conversations about your brand (and competitors) you should have more information to support your conversation of what the goals of your social media strategy should be.
Here is a great list of additional free tools to listen.