Based on the stacked bar graph data visualization technique introduced by ThemeRiver (PDF) and StreamGraph, MemeTracker [memetracker.org] represents the daily news cycle of around 900,000 news stories and blog posts per day from 1 million online sources, ranging from mass media to personal blogs. The system tracks more than 17 million different quotes and phrases that appear most frequently over time across the entire online news spectrum. The resulting graphs make it possible to see how different stories compete for news and blog coverage each day, and how certain stories persist while others fade quickly. In addition, one can analyze the media sites according to their "time lag" on reporting on a story.

See also LastGraph, Ebb and Flow of Box Office Movies and Tokyo: Right Now. Via Data Mining.