Have a PDF to print but hate to open Acrobat and wait? Go top System Preferences » Print & Fax, and click Open Print Queue for the printer you want to use. Drag the PDF into the window and it starts to print.
This should work with other files (Word, etc.). Some apps may start up to access their unique data, but for some files, this is a fast way to print and not have to run the app. Desktop printer? We don't need no stinking desktop printer!
[robg adds: A quicker way to do this is to simply drag-and-drop the PDF onto the desired printer in your user's Library -> Printers folder. This will open the queue and start printing directly (assuming the parent app doesn't need to launch to print).]
Mac OS X Hints