Hahah! Here's the TDD post:
http://thedailydigi.com/all-about-credits/
I think there is also a free tracker mentioned in the comments somewhere. But I think it was for PSE...anyway, hope it might help. And I do believe that CS5 itself can keep track of file names of everything you add. Just haven't taken the time to research that feature and see if it's already in my CS4, too.