Inductive User Interface
Take a look at the Microsoft Inductive User Interface Guidelines: "[T]he IUI model suggests how to make software applications simpler by breaking features into screens or pages that are easy to explain and understand."
The example application they use to illustrate IUI is Microsoft Money. I started using Money 2001 towards the end of last year. The examples they use to contrast are Money 99 and Money 2000, but 2001 has largely the same interface as 2000. I was somewhat concerned about using the program because financial management software was one of very few major types of software that I didn't have extensive experience with, and certainly the only mature genre of software that I didn't already use daily.
Money's turned out to be a charm. It's actually almost fun to use, but part of that is because of the sick, sad pleasure I take from balancing my checkbook. The remarkable thing about Money is that it is an incredibly feature-rich program, (the linked article mentions over a million lines of code) but I always feel as if I'm no more than 2 clicks away from anything I want to accomplish.
Looks like IUI is a winner, by my small, highly-subjective experience. But the screen shots of Windows XP seem to show the "HTML View" of Explorer windows evolving into an IUI interface, particularly for tasks dealing with digital media. The stock example seems to be managing photographs, either from a scanner or digital camera. Judging by how much trouble my dad's been having with that exact task, despite his extensive experience with computers, IUI might be able to help. It certainly can't hurt.