Pulse Dialing

It's debatable whether this skill is actually obsolete. Pulse dialing is still usable in many areas of the world. It is a simple technique whereby the phone is “hung-up” and “picked-up” repeatedly in rapid succession.

Put simply, pulse dialing is the equivalent of tapping on the disconnect button of a telephone quickly and repeatedly with the number of taps equaling the value of the digit to be dialed: 1 tap for a 1, 2 taps for a 2 … 9 taps for a 9 and 10 taps for a zero. The taps must be quick (something like 50 milliseconds apart) and evenly spaced.

This skill is particularly useful in those hostage situations where you only have your nose free and the buttons have all been removed from the touch-tone phone. A few quick taps of your nose on the receiver and you're one your way to freedom.