Google Elections Video Search Gadget
It uses " speech recognition software to automatically produce rough transcripts of presidential campaign videos." You can get it here.
Using the gadget you can search not only the titles and descriptions of the videos, but also their spoken content. Additionally, since speech recognition tells us exactly when words are spoken in the video, you can jump right to the most relevant parts of the videos you find.
SearchEngineWatch.com says it "leaves a lot to be desired" because it only transcribes "fragmented snippets" of political speech. I searched for Kentucky and this is how it transcribed Hillary Clinton's speech the night Barack Obama clinched the nomination:
"sex is the media west Virginia and Kentucky why don't we go and."
I'd say that about sums up the campaign so far.
