Todd showed me twitter4teachers today at training and I have been nerding out all night :)
However, he also showed me an even COOLER feature to use Twitter, TweetDeck. I signed up for Twitter 2 months ago and haven't used it. It seemed pointless and annoying, to be frank. Todd encouraged me to try it again using both twitter4teachers and TweetDeck and I have spent all evening on Twitter! (I guess it can be addicting).
TweetDeck allows you to organize the people or organizations you follow into groups. This makes everything more visually pleasing to me, and far easier to use. You can post your tweets and reply to direct messages through TweetDeck, as well as search for topics that you are interested in following.
Check it out, its pretty rad!