I have been on Twitter (@booksNyarn) for a couple months now. It has been a good way to check in on friends, colleagues and interests. You get to "follow" people - and people follow you.
Each Friday is a Follow Friday. Users will hash tag (#) their subject in the tweet and then people can search Twitter for those conversations based on that hash tag. The top ones will be shown on your Twitter profile.
Today was started #followalibrarian and I was awestruck by the amount of virtual colleagues and cohorts I could find. New connections for work and play are always a find. I went from around 60 followers to over 100, and met some new librarians along the way.