Just a cautionary note. Some older ports may not be fully capable of switching to inputs. I have been designing a new breakout board, which will use LPT2 as mainly inputs, and found that the built-in port (which had been LPT1) could be made to take inputs, but the output drivers were not disabled. This caused a current of about 40ma to flow through any switch attached to the input. Not a problem for switches but a problem for the port itself. It was also not really practical to drive them with logic. In the end I've had to specify that it must be used with a modern ECP/EPP card.
There is some good info on the web on parallel ports which describes the different cicuits used and problems associated with them. Can't point to it at the moment, but I think I just did a search for parallel port interfacing.
Tony