A friend at work shared this link to me. It's an interesting video/animation that fills in a presentation about what motivates workers. While the video is fairly short (about 10 minutes) it feels much longer because there's so much content there.
I saw something very similar in the Harvard Business Review a few months ago, drawing pretty much the same conclusion: if the work is strictly mechanical, money is a motivator. If the work requires any cognitive skill, money is no longer the motivator.
This is exactly what we see in the IT industry today. Linux and Apache are huge forces, yet in most cases, the people who develop Linux and Apache aren't doing it for the money. But look at Microsoft - I wonder, is it really so surprising that Microsoft seems sluggish?