Twitter is a service for friends, family, and co–workers to communicate and stay connected through the exchange of quick, frequent answers to one simple question: What are you doing?
My own experience with Twitter began with reluctance. I am involved in Facebook, Linked In, Google Reader, and obviously, WordPress. I enjoy and fully support social media and all that comes with it, but to add one more thing was overwhelming. This was my feeling before I tried Twitter, but now I love it! Twitter is an easy way to connect with people that you would have never met without social media.
Influential people from companies such as Dell, Georgia Power, GM, and others are on Twitter and can answer questions about the professional world that are specific to their company. It is just a matter of typing in the name of a company that you are interested in, and then following those who are associated with that company.
An example of how it has helped me personally: I have a conference coming up and needed to let my PRSSA members know what to wear. Posted the question what to wear to a social event in the evening that is business professional? Brett Pohlman, a PR Professional, responded with what to wear and the reasons why. (Continue to dress professionally, even though it is a social occasion. Maybe a dress that is professional, being myself, I would not want to wear a suit.)
I would definitely recommend becoming involved in Twitter, it is an experience that can help you gain contacts in the field that you are interested in as well as making an online reputation that will help you in the future.