Where does it come from? What is it?
Well, if you're disheartened by my previous post about licensing your idea, here's the punchline: Real business creativity comes from boundaries.
Inventing something cool that can't be implemented isn't creative. It's mostly a waste.
I think that inventing the unimplementable is a fine hobby, but it's also a bit of a crutch. Yes, of course we need big visions and big ideas, but not at the expense of the stuff you can actually pull off.
So, let's get specific:
If you've decided you want to create a breakthrough in your area of expertise (say Ajax coding), then either be prepared to launch and run it when you're done, or have a clear licensing strategy in mind, one where you're not the first person in history to pull it off.
If you've decided to invent a great idea for a book, better be ready to write it too, and either find a publisher or publish it yourself. There's no market for book ideas.
If you want to do creative ads, it helps to have clients willing to run them.
These constraints are the best part of being creative, as far as I'm concerned. I couldn't imagine writing Superman comics. The rules are too vague. There are too many choices. In non-profits and organizations and even in politics, the rules are pretty obvious (sometimes they're too obvious). So the real creativity comes in navigating those rules in a way that creates a breakthrough.
One of my favorite triumphs of all time happened on my first day of work at my first real job, 1984, Cambridge, MA. No voice mail in those days. I was employee #30. I walked in and there was a plastic carousel, about 18 inches in diameter, with 40 slots in it. Like thin slices of pizza, but 4 inches deep. Each slot had a sticker with a name typed on it. Not in any order, particularly.
Every day, when you went into work, you had to spin the carousel around and around until you saw your name, and then grab whatever pink slips had your phone messages on them.
Now, there are 100 better ways to do this system. Faster and easier. But 99 of them required getting a new carousel or device.
Instead, I grabbed a paper clip and put it on my slot. I could find my slot in a heartbeat now.
Within a day, the carousel was covered with flags and widgets and more. Problem solved.
See the rules. Keep most of them. Break one or two. But break them, don't bend them. (thanks to Curt for various inspirations).