Real Kiosk is a Firefox extension that defaults to full screen, disables all menus, toolbars, key commands and right button menus. Alt+Home still takes you home.
Here are a few things you can edit and enable via this add-on:
You can enable Navigation toolbar by adding the following to user.js:
You might want to remove the print dialog by adding following lines to your user.js:
Notice that the user can still close Firefox with for example Alt-F4 and get access to your computer. You might want to prevent this with a suitable utility program for your operating system.
Pick up this interesting add-on at the Firefox Add-on website.