I was reading a GJ thread about JIS screw drives and I was not familiar with them, I found this link that explains alot of different screw drives and their original design and purpose. I'm sure this may be old news to alot of you but I found it intesting and thought some others may as well, as an example I remember hearing that philips drive were invented by someone named philips, but what I didn't know is that they were intentionaly designed to "cam out" of the screw head on purpose.
http://en.wikipedia.org/wiki/List_of_screw_drives
http://en.wikipedia.org/wiki/List_of_screw_drives