Hands down, the best, most fascinating and entertaining keynote speaker I ever heard was the late then-Capt. Grace Hopper of the US Navy. Talking about her involvement in the development of COBOL, the "first" computer bug, and her ubiquitous "nanosecond" prop (a 1-foot length of wire, the distance light travels in that time) had the audience howling for more. Especially when she described how, one time, she thought she'd try illustrating a microsecond also. All was fine until she got to airport security ........