Enter two or three search terms separated by commas and press the 'Search' button or type Enter/Return. After the data is retrieved a Venn Diagram is shown which illustrates the rate of tweets containing the search terms in the various combinations. See the Neoformix post on Twitter Venn for more details.
This was created by Jeff Clark. If you are intrigued by this application you may wish to check out Neoformix to see my other work including TwitArcs, Twitter Spectrum and Twitter StreamGraphs.
Thanks to Processing for the development tools and Twitter Search for the data.