Originally I had no desire to join Twitter. Facebook keeps me busy enough and I thought who needs one more thing to check daily? Plus, as my brother always said, "Twitter is like Facebook without the cool stuff". Finally, because of this class (plus a contest from my favorite peanut butter maker, "The Peanut Principal") I decided to jump in.
I decided to start small so I wouldn't become overwhelmed. I played around and decided to follow the following: The Peanut Principal, Walt Disney World, Once Upon a Time (the TV show) and Sue Kowalski (president of SSL/NYLA). Slowly I added a few more people to follow, including a Bento box expert. I'm still keeping my list on the shorter side but am enjoying Twitter more than I thought I would. It's a great way to find out quick tidbits of information although sometimes I do find myself wishing for longer more informative posts.
As far as using Twitter professionally, I haven't done it yet but could see uses for it. One way would be to Tweet a book suggestion of the day or list new books through it. Meetings in the library could also be announced this way or I could come up with a Trivia question or fact of the day to send out.