Year on year visits to Twitter are up 8 fold. In the past three months, visits have more than doubled and traffic continues to climb, up 60% in the past month.
In the short time that I have used it, Twitter has grown quickly to play a major part in the way that I interact with fellow colleagues and professionals from around the world.
Tweetree puts your Twitter stream in a tree so you can see the posts people are replying to in context. It also pulls in lots of external content like twitpic photos, youtube videos and more, so that you can see them in the stream without having to click through links.