"Simplicity is the ulimate sophistication." - Leonardo DaVinci
Why is the iPhone so popular? It packs a ton of sophistication into a very easy to use device. Software designers work tirelessly to ensure that their products are functional -- packing in every last feature to make a robust product -- yet don't make applications that are easy to use. Sometimes the best pieces of software are those which are missing features but are insanely elegant in their usability and design. The best web pages aren't riddled with verbiage and non-essential photos -- they have the perfect combination of words, images and features to achieve their goal. Compare the home pages of Google and Yahoo! to for an example.
Pablo Picaso created a suite of 11 lithographs called "Bull." Over his career, he worked, refined and simplified Bull to get to its bare essence.
Bull started here:
And ended here: 
As ArtyFactory.com succinctly points out "In the final print of the series, Picasso reduces the bull to a simple outline that is so carefully considered through the progressive development of each image, that it captures the absolute essence of the creature in as concise an image as possible."
Moral of the story: Reduce. Refine. Simplify. Continually improve. Make your software, web site, business model, whatever as simple as possible. As Albert Einstein said “Everything should be made as simple as possible, but not simpler.”