I am a business guy who loves Steve Yegge:
The requirements-gathering process they teach you typically involves finding some "potential customers" for your product, and interviewing them in a nonscientific way to try to figure out what they want out of your proposed product. Or service. Or whatever. It doesn't really matter.
Potential customers can be hard to come by, especially since you're building something that nobody will ever, EVER want. Well, that's getting ahead of myself.
Go read this awesome post.