Wow, lot of food for thought so far.
I forgot about custom knives. The knife industry seems like most technology industries - there is usually the person who invents something, then the company that first successfully markets or mass-produces it. Usually the inventor is not as well known to the public and doesn't get the credit that they deserve.
Some tactical knives being mentioned also. I don't follow developments there much, since I use other defensive tools. So, they weren't on my mind, but clearly are of great importance.
Also, a lot of knives brought up based on a unique opening or locking mechanism. I'm surprised that no one has mentioned the traditional slipjoint patterns like trapper or stockman.
BurkStar, information like yours is the reason why I want to find a book. If anyone has suggestions for reading material, I would like to hear.