I like to use Firefox in full-screen mode (hotkey: F11) on my netbook. Unfortunately, Firefox hides the tabs and navigation bar and only shows the bar when your mouse pointer is on the top of the screen.
Luckily, it's easy to modify this default setting:
enter 'about:config' in the URL-field
confirm that you really will be careful
set the 'browser.fullscreen.autohide' setting to false (double-click on the line)
This gives me a Chrome-like browser experience with Firefox on Ubuntu, while maximally using the small screen size.