Here's a cool piece of trivia. Garo Yepremian was the last NFL player to not have a facemask on his helmet. He made a few games into the 1966 season with the Lions before Lombardi's Packers convinced him that it was a good idea to have one.
Here's an old ESPN article that mentions it:
http://espn.go.com/blog/nflnation/po...the-single-bar