A friend of a friend wrote a great piece in Vanity Fair about getting fired for tweeting. He points out that "tweeting your mind and keeping your job can often be incompatible," and that this might be because "tweets tend to be banged out on a cell phone or BlackBerry in a matter of seconds." Essentially, people don't think before they tweet! 

 Just ask yourself this one question before you send a message out to the Twit-o-sphere. "Would I say this to my boss's face?" If the answer is no, slowly step away from the keyboard.