(Circuit details: http://www.epanorama.net/circuits/parallel_output.html)
I also combined it with laser gesture recognition to turn four appliances on or off using a laser pointer for Engineer 2007. I guess everyone loved it. :)
If you can make pcbs, and are interested in a simple little circuit to provide opto-isolator protection to 4 parallel port inputs, and relays on the other 4 bits, as outputs, then check the offer on....
... which is a little way down the page, next to the Google panel, in the paragraph starting "I have a third generatino, inexpensive...".