Wikipedia reports a not-all-that-widely-known fact about Donald Knuth (Knuth wrote what many consider to be the bible of computer programming; he is also, in many ways, the father of much of what is now commonplace in the technology of displaying fonts on computer screens):
In issue 33, Mad published a partial table of the "Potrzebie System of Weights and Measures", developed by 19-year-old Donald E. Knuth, later a famed mathematician. According to Knuth, the basis of this new revolutionary system is the potrzebie, which equals the thickness of Mad issue 26, or 2.263348517438173216473 mm. The system also features such units as whatmeworry, cowznofski, vreeble, hoo and hah.
(Thanks to Mark Dionne for bringing this to our attention.)