One of the biggest benefits any architect can provide is to focus on usability (IMHO). Just plugging into a power strip is the perfect example.  In power strips the available plug in spaces either run horizontally or vertically.  Yesterday, I came into work to plug in my AC adapter for my new Zune.  I had a power strip that ran vertically with 2 oversized plug ins.  Each one took up 2 spaces on the the strip overlapping. So no room to plug in the third adapter. I hijacked a different power strip that ran horizontally.  This strip allowed me to plug in each one of the oversized adapters. So which was better?

My point is this.  Software design for usability works the same way.  By truly understanding how the software will be used and anticipating how it may be used are key for architects when designing systems.  Scott Hanselman recently had a podcast, Show 65, where he spoke with Martin Fowler and David Heinemeier Hansson concerning usability among other ideas.