Installed Printers (Mac)
Mac OS X
This property list (plist) on a Mac OS X machine will tell you what types of printers have been installed on that system. Be advised though, that a printer may have been uninstalled/removed by the user and if they have not restarted their computer, that printer’s entry will persist until the computer is rebooted. This plist will then be overwritten to reflect the change.
Apple Developer Tools: http://developer.apple.com/technologies/tools/xcode.html
Forensic Programs of Use
plist Editor that is provided with XCode