[ktRolster]

His ideal vision is always described in very abstract terms. If he took the care to write it down precisely, what it should look like, I'm sure there would be hundreds eager to build it for him.

Look at Squeak. http://squeak.org/ The idea that you should be able to dig in and modify things is very powerful.

Another way to look at it is in terms of discoverability: you are at one level of understanding (using the phone, clicking on things), and it should lead you to a deeper level of understanding (perhaps moving things around, modifying them). At each level, there are hooks inviting you deeper, drawing you in. Ideally you get down low enough to start programming, to actually understanding how assembly and the CPU works, so there is no longer any area of magic.