Twitter
Twitter is a popular micro-blogging site. You can post messages that are within 140 characters using SMS, IM, mobile phones, and a browser. Because of its ease of use, people have used Twitter to post messages about happenings about the world and the Internet; some people have also used it to post their current status. Twitter has been used by several self-tracking tools as an input mechanism, such as your.flowingdata, tweetyoureats, Grafitter, Mycrocosm, Daytum.