A couple tweaks that allow you to change the behavior of the location and tab bars while in Full Screen mode. By default when you enter full screen mode (F11) in Firefox 3 the location and tab bars disappear.  If you put your mouse up the top of the screen, they will pop back up.

If you want the location and tab bars to always display (Firefox 2 behavior) made this change:

1. In a new tab type about:config in the address bar and press enter
2. In the filter field type browser.fullscreen.autohide
3. In the results listed double-click on browser.fullscreen.autohide so that the value defaults to FALSE
   

When you first activate full screen mode, the location and tab bars slide up. To disable this animation:

1. In a new tab type about:config in the address bar and press enter
2. In the filter field type browser.fullscreen.animateUp
3. In the results listed double-click on browser.fullscreen.animateUp
4. In the pop-up box type: ‘0‘