You can listen to a discussion of Karl Popper on the BBC Radio 4's In Our Time. I haven't listened to it yet but I will. I notice too that it's only the most recent show that's available for podcast. The older shows, which are all archived and easily available, can only be listened to via their site. Which is still all right if you are sitting at "work" with nothing much to do.
From the blurbage:
Popper wrote: “The more we learn about the world and the deeper our learning, the more conscious, specific and articulate will be our knowledge of what we do not know, our knowledge of our ignorance”.
But of course this is no substitute for reading Popper himself. I recommend Conjectures and Refutations and, of course, The Open Society. Also The Poverty of Historicism. They're a little bit difficult; The Open Society takes you on a pretty gruelling slog through Plato and Marx, but it is worth it. And the fact that, per the BBC blurbage, "someone close to Margaret Thatcher" was interested in his ideas should not put you off.
The best book about Popper is Bryan Magee'sslim little book Philosophy and the Real World; An Introduction to Karl Popper. Magee is an interesting writer on his own account as well as a trustworthy explicator of Popper's achievement. He is also possibly the only television personality who is an actual working philosopher. He writes beautifully and is an authority on Schopenhauer and Popper. His autobiography, Confessions of a Philosopher is fascinating; it makes thinking about philosophical problems (real ones, not fake word ones) seem exciting. Because it's exciting for him, I guess. So he made a career out of trying to bring that excitement to a bigger audience, and succeeded rather well.