If I'm creating an application that needs some sort of non-technical person interface (which seems to be most of the time these days..) then I'll use a web interface (hopefully with mod_perl). Although web interfaces aren't as elegant as a full blown GUI, they massively simply things such as deployment, fault tracking and reporting/logging.

In my experience, the part the 'whole world' sees is usally about 20-30% of the application... the rest is the administration interface.