[EricVanWyk]

This is possible, but it is very very ugly. And when I say ugly, I mean that a Spartan mother would have left this solution on the side of the mountain.

You may remember this basic method from the days of PBASIC.

Take the pot and wire it such that its middle pin goes into one of the IO pins on the parallel port, and one of its other pins goes to the ground pin. Wire a capacitor in parallel with the pot.

Voila! You have an RC network whose time constant varies with the pot's value.

Set the pin to an output. Wait a small while. Set the pin to an input, and time how long it takes for it to go from 1 to 0.

The reason this is not awesome is that you don't have a great idea of exactly what voltage will cause a transition from 1 to 0. In fact, the spec for the parallel port probably doesn't even say that it is repeatable.

However, you get what you paid for.

Enjoy and good luck!