When using the Spaces hot key (F8), if you hold the key, Spaces will appear, then disappear when you release F8. This great when you just want to get a bird’s eye view of stuff — press and hold, view, release and Spaces vanishes. And, this works as expected with the Spaces plus Exposé tip (Show all windows). Press F9 while holding F8, and you’ll see the All Windows view.
Also, another tip for those with notebook keyboards (or others?). On mine, F7 has a tiny icon of two screens. This makes an excellent ‘icon’ for Spaces, so I’ve re-assigned Spaces to that key.
Via Mac OSX Hints