Hey, I just came across this:
"The Invention of the Pivot Table: The concept that led to today's pivot table came from the halls of the Lotus Development Corporation with a revolutionary spreadsheet program called Lotus Improv. Improv was envisioned in 1986 by Pito Salas of the Advanced Technology Group at Lotus.
Realizing that spreadsheets often have patterns of data, Pito concluded that if one could build a tool that could recognize these patterns, then one could build enhanced data models. Lotus ran with the concept and started developing the next-generation spreadsheet." (from Pivot Table Crunching)
Yes, that's pretty accurate, and it's in an actual book! Neat.