Did you know that Stan Lee actually created the idea of the film cameo in 1961? Apparently, he took it to his publisher, Martin Goodman, and Goodman said, "Stan, it'll never work. The audience doesn't want to see a cameo. They want to see regular actors." As legend has it, Stan went home and was talking to his wife and she said, "You should create the acting subsets that you want to create." So, Stan did it. Then, a few months later, after the numbers came in for the first ever film cameo, created by Stan Lee, Goodman went back to Stan and said: "Stan, you remember that cameo thing that we both liked so much...?"
Later accounts indicate that it was actually Don Heck who created the cameo as Lee had just approached him with a handful of pieces of paper with the letters C, M, A, O, and E on them and said, "Don, I got an idea for a motion picture acting subset. Can you take these letters and form the word, as well as describe exactly what this particular subset will do?" Stan then went to great lengths to get people to think that he was the sole creator of the cameo.
The end. EXCELSIOR!
...that video was pretty funny though