A very good usability presentation
Even though this is geared for the iPhone, this usability presentation speaks volumes about what we as developers think our users can do (and not do). I regard the iPhone user interface as probably one of the best iterations in user experience in recent times, but that is just me. This presentation does show the oversights even the most avid user experience designers can make. I agree with many of the suggestions in the presentations and disagree with some. After all, you cannot make a device that is as natural as just talking to another human (even that is not perfect).
Check out this presentation.