Alan Kay, regarding his reaction to the iPhone in January 2007:
When the Mac first came out, Newsweek asked me what I [thought] of it. I said: Well, it’s the first personal computer worth criticizing. So at the end of the presentation, Steve came up to me and said: Is the iPhone worth criticizing? And I said: Make the screen five inches by eight inches, and you’ll rule the world.
http://gigaom.com/2010/01/26/alan-kay-with-the-tablet-apple-will-rule-the-world/
See also: Dynabook