If you used Spaces under Snow Leopard, you may have noticed that switching between Desktops using Ctrl+arrow keys is much slower in Lion.
To make switching a bit faster, you can assign a shortcut key to each Desktop in the Keyboard section of System Preferences.
I used F16 - F19 to switch directly to Desktop 1 - 4 respectively. On the full-size (USB) aluminium keyboards these function keys go unused otherwise. Switching is now as fast for me as it used to be under Snow Leopard.
[crarko adds: I haven't tested this one, but it sounds like it should work fine with the appropriate keyboard.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20110724082653835