A usb to parallel port adapter wont work. You need something like this:

http://www.planet-cnc.com/

Or:

http://www.zappautomation.co.uk/prod...roducts_id=202
(10% off there at the moment...)

As you can see it's an expensive way to do it. You save by not needing mach3, but then arguably that's not a saving as you could use the free EMC2 instead.

A PCI parallel port in the laptop may work ... not sure.