I want to use chrome to display a full-screen html page for a presentation. You can set chrome to fullscreen mode, but it seems the only way to exit is moving the mouse to
For firefox, the add-on R-kiosk doea a similar job: https://addons.mozilla.org/en-US/firefox/addon/r-kiosk/
I have used it before and it used to be pretty good for kiosk type applications. Haven't needed it in a while though.
To exit, you need to start firefox in safe mode and disable the add-on, which works very well for kiosk purposes.
Using my comment for an Answer:
Chrome implemented 'Kiosk Mode' in version 4.0.245.0. This is, essentially, a way to launch the browser in fullscreen mode with the Address Bar and Status Bar disabled. Some keyboard shortcuts (Fullscreen, for example) are also disabled.
On Windows: chrome.exe -kiosk http://yoursite.com/file.html
On everything else: chromium-browser --kiosk http://yoursite.com/file.html
Note: Use your 'exit program' keyboard combo to kill it.