Artifical rights

I've been thinking about writing a book for some time. I've always wanted to write the great American novel. You know, "It was a dark and stormy night..." and all that jazz. Actually, it'd be a sci-fi mystery novel. And I know I just need to do it. I've got a great idea, but I'm scared to say anything about it because it is just an idea, and we run into the whole "expression is protected - idea is not" problem. Once I get it hammered out, maybe I'll put it on the web under a creative commons license. But until that happens, I'll just have to hide my light under the biggest, darkest bushel I can.
Or, the alternative would be to write each chapter, put it on a site with a CC license that required attribution and allowed derivative works - maybe it could become some kind of bizzare experiment in collaborative authorship. Hmmmm... that's a good idea. Instead of going ahead with the first book I was thinking about, how about a collaborative space opera? I'll spend one hour per night - btwn 11:00 PM and 12:00 AM writing, six days a week, with Sundays off. At the end of that time, whatever I wind up with will end up in the House of Claire. I'm not saying it'll be three pages a day, but I will put it up there with the aforementioned cc license. Comments, critiques, and re-writes will be welcome. I need to update the House anyway. So, no cheating, no throwing up something I've already written, an idea of the world I'm creating... This is going to be a lot of fun.