Lion: Change Keyboard shortcut CMD + ALT + Left/Right Arrow for spaces OR Firefox's next/previous tab I'm using Firefox, where CMD + ALT + &larr; / &rarr; Arrow changes to the next / previous tab. This is an important feature to me. 

Since Lion, this shortcut changes the active space to the next and previous space, with no way to customize this. And I want to use spaces, just no with the keybinding. Firefox also won't let me customize my shortcut. How can I change one of those?

(Hint: the Firefox extension "keyconfig" let's you do a lot of keybindings-changes, but not the previous and next tab ones).
You can change Mission Control's keyboard shorcut from System Preferences/Keyboard/Keyboard Shourtcuts window or bind specific shortcut key for Firefox in same window.