[Irongeek] has assembled a good starting point for hacking network printers. It starts with a discussion of stock passwords and how to administrate printers using telnet. Next is finding printers using NMAP. You can actually use the JetDirect boxes as idle scan zombies to scan other systems without exposing yourself. Other topics include setting up direct IP printing, changing the display, and using Hijetter from the Phenoelit crew. The ability to capture and replay print jobs really demonstrates how insecure network printing is.