Trees and Minor Amounts of Intertwingling
PeterV's story of automated phone system vs. web (why is the phone system, which forces one to navigate a tree, easier to use?) reminded me of a story from Chris Fahey of Behavior. Chris was designing an interface for a mobile screen, I forget whether it was a PDA or a mobile phone. Of course he was forced to reduce the interface to its fundamental elements. He subsequently would keep designing for a screen that small even when working on websites, pretending he had only that much space and concentrating on the fundamentals of the interface.
I think that's why the automated phone interface is easier, there's no auditory 'room' to introduce clutter, indirectly leveraging Hick's Law.
Whereas websites are like our homes: the clutter expands to fill the available space.