My second-to-last bout in the software world was as a UI designer. I did the initial concept work for Windows CardSpace, a so-far-unsuccessful attempt to replace passwords with standards-based assymetric key technology hidden behind a user-friendly interface.
Well, it was supposed to be user-friendly. The combination of technological, political, legal, organizational, and commercial forces at work, plus my own extremely limited abilities in this area, resulted in a hodgepodge of a UI that tanked in usability testing. To say that our subjects clawed their eyes out and screamed when confronted with our work is to understate the severity of the situation.
Good times.