The
handshake and crackling noises that
modems make to each other in order to
communicate. The ability to speak this language was wished for by many
geeks, who thought it'd be neat to dial up a
bbs, hiss, beep and squeal into the reciever, and be able to play
door games from work without even having a computer.
Of course, it's slightly more difficult these days, as not only do you need to learn to hiss and squeal, you also have to speak the gibberish known as TCP/IP.