My daughters have always thought that the "black box" that I use so much (the command prompt shell) was hilarious. I type my cryptic little abbreviations, press Enter, and then more text goes scrolling up the window and off the top. I tell them how in the early days of PCs, and even pre-PC computers, the whole computer screen was just one big version of that window, and how before that people did the same thing with a keyboard and a printer, and the girls roll their eyes and patronizingly say "great, Dad!"

Once, after IMing with a colleague about some work-related issue, I wanted to make my thumb drive the default drive in my command window, and I accidentally sent the colleague the instant message "f:". Then I realized: the command prompt window is like IMing with your operating system. I pointed out to my daughters that one of their favorite applications had plenty in common with my command prompt window: they type their cryptic abbreviations (ROTFL!) and then wait for the response, which is text scrolling up and off the top of the window. I think their response was something along the lines of "great, Dad!"