Via Bill de hÓra on Twitter, a great article from ex-Gmail/now-Friendfeed hacker Paul Buchheit:
The point of this story, I think, is that you should consider spending less time talking, and more time prototyping, especially if you're not very good at talking or powerpoint. Your code can be a very persuasive argument.
The other point is that it's important to make prototyping new ideas, especially bad ideas, as fast and easy as possible.