I am a Twitter user. Feel free to follow me @hhibner. I do not have protected tweets, so I don't have to approve who follows me. I do look in on recent followers every now and then (and am always surprised at who's following me!), but I don't moderate new followers. Here's why.
Twitter, for me, is a professional network. My own feed crosses the line between personal and professional, but even my personal tweets are very generic. I don't worry about who sees my tweets because I never tweet anything I wouldn't say out loud. My boss can follow me, my mother can follow me, my co-workers can follow me - it doesn't matter to me who sees my tweets. Remember my post about integrity and intent? I follow my own advice. I also follow Mary Kelly's advice as she lays it out in her post about brand management.
Twitter is pretty big in librarianship. All the "cool kids" (as Mary and I like to call them) in the library world are on Twitter. I follow people like David Lee King, Michael Stephens, Bobbi Newman (Librarian By Day), Sarah Houghton-Jan (Librarian in Black), and a host of others (182 others to be exact!). These are people on the cusp of library science. They were the first to break news about the Harper Collins Overdrive checkout limits, the merger of Ebsco and H.W. Wilson, the Kindle announcement of Overdrive compatibility, and various other big news announcements affecting libraries. They are the first to respond to these announcements, too. They have blogs that they tweet about, alerting me to new posts on these issues.
I also love the occasional patron tweet. These are one-liners about interesting, difficult, or weird reference questions that real librarians are experiencing. We all sympathize with them and we know where they are coming from. Patron tweets, done well, do not name patrons or describe them in enough detail to "out" who they may be in real life. They may say something like:
I do "weed" my Twitter account fairly often. I may start following someone that is re-tweeted by someone I admire. I may start following someone who's blog I discovered. I follow them for a week or so and then make a decision: am I getting enough value from their stream to keep following them? If not, they get un-followed (sorry! It's nothing personal. I'm sure they're lovely people in real life.) I try to keep my Twitter stream reasonable enough that I don't miss anything too major. When I log in, I only spend about 15 minutes reading back-tweets. If I follow too many people, I miss too much and the whole thing is useless. I don't follow everyone who follows me because I just can't keep up. I follow people who tweet regularly enough for me to get to know their specialty, but I do get annoyed with people who tweet constantly all day, every day (but who don't really SAY anything useful). Again, nothing personal...it's just how I've chosen to use my Twitter time.
So, for me, Twitter is a way to keep up with breaking news in libraryland (as well as in my hometown, since I follow the local news tv channels and newspapers). It is a way to find hot-off-the-presses blog posts. It is a way to keep up with what library movers and shakers are working on and thinking about. It is a way to keep a sense of humor about working with the public.