Using the Lexington Concordance ( http://www.lexconcord.org/ ) site, you can search to find how many times a certain keyword has appeared in a member of Congress's floor speeches—or at least, how many times it appears in transcripts for their speaking time.
It can be fairly instructive on understanding what issues my representative, @RepRickLarsen, likes to talk about in the House and what causes he's passionate about. Let's try finding some key words...