Check out this very cool site, Podzinger.com—it let’s you search for a word in a podcast. So if you got there and search on "EconTalk" it will pull up a bunch of EconTalk podcasts. Then you can easily search for a particular word within these podcasts (see the drop down menu in the search engine to search just EconTalk) So if you search for Cuba, it will pull up all of the EconTalk podcasts where Cuba is mentioned.
That would be cool enough. But it’s much better than that. Once you search for Cuba, you’ll see an excerpt of the podcast with the word "Cuba" highlighted. You can click on the word "Cuba" (or any other word in the excerpt) and it will start playing the podcast at that point. Incredible. Actually, it will create a player for the podcast with all the mentions of the word "Cuba" flagged within that podcast so you can just click on them.