If you still think that carrot-and-stick is still a good metaphor for how to motivate people then you should watch this 10 minute animation of Daniel Pink giving an overview of his book Drive:
Daniel Pink: Drive
A 40 minute version of the who talk it’s available here.
If you think that Daniel is being a bit idealistic in his interpretation of the science then you should also watch Clay Shirky’s presentation to TED on Cognitive Surplus.
That’s right – money doesn’t motivate other than in the very basic of activities.
I love the way that these animations are a bit like an active rich picture.