Old puzzle, new puzzle

An old puzzle asks how a barometer can be used to measure the height of a building. Answers range from dropping the instrument from the top and measuring the time of its fall to giving it to the building's superintendent in return for a look at the plans. A modern version of the puzzle asks how a personal computer can balance a checkbook. An elegant solution is to sell the machine and deposit the money.
(- Jon Bentley)

Any other answers?