Speaking of intercoms, the house I grew up in was equipped with an intercom system. In every room, there was a box on the wall where you could push a button and announce something to the rest of the house -- or, more likely, holler someone's name. It also had a radio attached, so you could play music throughout (or only in certain rooms, by using the master-control in the dining room). You could even, with the master conrol, turn the box in any room into listen mode, so you could eavesdrop on anyone. Wow, I just remembered that. It didn't get used much, though. In fact, my father still lives in that house, but the P.A. system hasn't worked for years.