Today's news of a large study of tweets, as a way to gauge people's rise and fall in moods, made me happy. I'm not as concerned as Gothamist with whether the study is properly scientific; 'Ist claims that it's not, but doesn't say why. Rather, my beef is that the paper will appear in Science and not everyone who wants to can read it.
That said, here is a perfect example of how all those supposedly frivolous Web 2.0 natterings can lead to real research. There's a reason the Library of Congress is archiving tweets--because they are now part of our written record. It's a new era everyone; get on board.