Great minds think alike. I submitted a similar design a couple of weeks ago... http://www.threadless.com/submission/229307/Fertile_Mind/showmore,designs based on a design I created a few years back... http://serkworks.com/graphicdesign/fertileminds.htm
And I'm the first comment over there! But I didn't remember it when I made this. Actually, I had a tree drawing, and I was told by a friend that it looked like a brain... It's the same concept, but I think it's different enough. Thanks for the comments!
That's happened to me before, when you come up with a great idea and then google it and it's already been done. Then again our concepts might not have been that great after all, don't think mine made the cut, good luck on yours!
About my design