Is there a printer server / router available that will allow me to print from my laptop without the need to leave the desktop on? The XP program requires it to be on, and I would like to access the printer without having to turn on the desktop.

The Linksys WPS 54G(wireless printer server) among others will work.
Just need to plug Printer into wireless server.
Both could be placed anywhere together.
You do need a wireless router.