TAK-TAK-TIPTIP-TSUUUT. Twenty minutes of amazing mimicry. I found this a few years ago via Metafilter, and it comes up every damned time I think of a typewriter. It's Mr. Winslow's eyes that make it most memorable, particularly around 8:20.
Our capacity to make simple noises complex, if done right, is an amazing thing.
And yes, I have watched the entire thing. If one thing's for certain, you'll learn more about human creativity and machines by watching it than if you were forced to watch Transformers a dozen times (Ermahgerd, Decepticons).