http://www.techcrunch.com/2009/02/15/mining-the-thought-stream/

As online content is updated more and more often, traditional search engines are becoming less and less effective at knowing what is going on right now. This article looks into the concept of “real time search”, and what makes it so powerful and interesting (in short it allows us to see change and trends as they occur, so we can learn from and act upon them).