Yes, I have one. When you sign up, you can choose to "follow" people. Their tweets will appear on your homepage at twitter.com, or on your twitter feed on your mobile device if you get the app.
Once you have an account, you can "tweet" articles of interest to your friends, or you can post updates about what you're doing (140 characters or less).
I use twitter daily in my TV news job; I'm following a number of political figures, local organizations and newsrooms. Often I learn things from Twitter before they hit any other source.
at 1:26 PM on Jun. 19, 2012