Here’s an interesting video of Edward Tufte reviewing the iPhone. (Warning: it’s a huge file and takes forever to load fully). He seems to like the iPhone overall, but does have a few valid critique points.
“To clarify, add detail” and “clutter and overload are not an attribute of information, they are failures of design.” Seems the iPhone interface are guilty of both, and they’ve chosen to throw out information rather than fix the design (according to Tufte).