Every time I watch my two-year-old son driving his iPad I marvel at the elegance, simplicity and intuitiveness of the iOS user interface, and I wonder about those mostly-unknown geniuses who designed it. This weekend I watched a presentation by Bret Victor, who is one of those geniuses. This is an excellent talk on many levels.
And when you are done take a look at Bret’s site for other amazing stuff. Just don’t use Internet Explorer; I suspect Bret does not like IE for some reason.