A friend of mine told me a story of a project from over ten years ago. Part of the product design was that it would include a bunch of skins (visual styles). The development team had written up the skinning infrastructure, but the company which was hired to create the actual skins hadn't delivered anything. My friend's assignment was to test the skin-switching interface, but since there were no skins, there was nothing to test.
My friend was responsible for testing a bunch of other product features, so it's not like the days were spent thumb-twiddling. But eventually, it got to the point where the automated testing for most of the other features was nearly complete, and at the weekly status meetings, my friend would ask the representative from the company that was hired to deliver the skins when they might send over the first two or three. "I don't need all twenty skins, just two or three so I can test the skin-switcher."
At the meetings, the company representative always answered, "Yes, we know you're waiting for it, but designing these skins is really complicated stuff, and it's pretty slow going."
My friend wondered, "How hard is this, really?" A visit to the development team quickly produced the same tools and documents that the skin design company was given, and in a few hours on a Saturday, my friend produced a brand new skin. Since my friend was a big Star Trek fan at the time, the homegrown skin was naturally based on the science fiction series, created by surfing the Internet and downloading pictures and sound effects. There was obviously no way the company could include this skin with their product, but at least it was something to test with. The skin-switcher finally had something to switch between: You could have the standard look or the Star Trek skin.
At the next meeting, my friend once again asked the representative from the design company when they might deliver a skin or two and received the same runaround as usual. "It's a lot harder than we anticipated, but we're getting close, so who knows, you might have something in a few weeks."
Except this time, my friend had a response for them. "Oh, maybe I can help you guys out. I threw together this skin in just a few hours. Here, let me show you." And then followed a demonstration of the Star Trek theme. It had a lot of rough edges (for example, the sound volumes weren't leveled), but it certainly did the job as a demo.
As if by magic, just a few days later, the company that had been contracted to produce the skins managed to overcome all the obstacles that had been plaguing them up until now, and a steady stream of new skins started arriving.