Google has launched a new search option that allows users to look at an archive of tweets on any given topic in a timeline format. Users can essentially "replay" the public Twitter conversation in th order in which it each piece occurred. To utilize the feature, users can go to "show options" on a search results page, and select "updates". There's a chart at the top of the page that lets you select the year, month, or day, or click any point to view tweets from that time period.