Richard Stallman is another example of someone who gives the same handful of speeches over and over (many times in almost exactly the same words). I've heard him describe over and over again the wastefulness of not being able to write software to interact with a university printer because the printer manufacturer choose to keep the necessary details secret.
his copyright and community talk has stayed with me since I heard it 12 years ago, it certainly was special (well argued) and left a lasting impression.
