A quick note about the tweets- I like the quick short reaction to information or statements. Sometimes it seems like I am listening to a conversation between other people, which I guess it is. I found some of the tweets that provided more information or referenced other sites were of greater value to me as I just browsed. I can see how this can be fun and useful as the followers have more contact with each other.
In the classroom, I am sure that as I become more active with this tool I would see more applications, but right now it seems that it would be a great way to get each and ever student involved in a topic of discussion. Art is a discipline that wants the viewer to bring to the discussion their personal experiences and interpretations- this would be a great way to do it.