The best presentations engage us emotionally, and tell us simple stories. This is a brilliant 20 minute talk for TED by Hans Roling an expert on global development and poverty. it presents an optimistic view of the future and an optimistic view of how far the third world has moved over the last 30 or so years. Watch the software! Google has snapped it up already.
Watch it and watch it to the end. Someone said it was a, literally, jaw dropping ending. I would describe it as making something that is hard to swallow, easy to comprehend!