We have a little official event in the office and need to run Firefox in kiosk mode. Check out this tutorial.
In short:
Simply go in the Mozilla Firefox directory open the chrome folder locate the browser.jar file and extract the browser.xul file. Edit the browser.xul file with an editor of your choice. If you know how XML works just remark the tags for the GUI components you don’t want.
My browser.xul is a little more restrictive then the one in the tutorial (no printing at all).