bookworm:

Search for trends in hundreds of thousands of s at Search across every word from 25 years of the Simpsons (at least, the ones that made it into closed captions) by episode, season, or even time within in the episode.
A particularly trivial example of how a Bookworm Browser can open up your texts.
Click on the chart to read that particular line from the monorail song you have memorized, anyway.
Some more explanation is here