Bored? Try Twitter search
It is not immediately obvious, but Twitter does have a search feature. It is hidden down at the bottom of the page:
(c) 2009 Twitter About Us Contact Blog Status Apps API Search Help Jobs Terms Privacy
You can also go directly to http://search.twitter.com/.
In addition to searching all Twitter messages for keywords, it also tells you what search keywords are currently most popular. For example, at this moment the hottest topic is the O'Reilly Tools of Change (for Publishing) conference, right here in New York City.