A friend is looking for a printer which can be plugged directly into a Windows 2000, Windows XP, Windows Vista, and Mac OS X (Windows 98 would be nice, too, but not holding my breath) machine and start working without the need for driver installations (basically, the printer is going to be situated in rented accommodation and any installation disks are bound to go missing).
He's basically trying to make it so that the folks in the homes can take a cable, plug it into their computer, their computer will recognize it, and go, making it as easy as possible for everybody involved.