Google Labs has a new project dedicated to indexing audio content, GAudi. What it does is index YouTube videos using speech technology to let you, the user search for any videos containing spoken words of your choosing. Those videos with the terms are shown in order of relevance and you can jump right to the sections of that video, marked with yellow bars on the progress meter (see below.)
So far, GAudi is only available with political channels - a pretty good place to start. Search the term, phrase or topic that you want to hear the candidates discuss and you get it. You can filter the channel by "All Politicians," "McCain," or "Obama." After searching, in the left bar, you will see corresponding videos, complete with how many times your search term(s) was mentioned in that video. Also, once your video loads you can "Search inside this video" to get more results, and closer to what you're ultimately looking for.
It's yet another step Google is taking towards a truly "Universal" search. Perhaps podcasting isn't dead after all, just in hibernation? Would you be more willing to download and listen to podcasts if they showed up in your everyday search results?