Use the Dock without the mouse!
The mouse is really a slowdown for productivity compared to the keyboard. One of my greatest productivity boost came from using the tip about the menu bar (Ctrl-F2). I think this one is the next best one! It is a keyboard shortcut for the Dock. With this, you can easily access the Dock with "Ctrl-F3". You can then move around the Dock with the arrows and open up application in a snap! You can also leave the dock with "Esc". On a portable, you might have to use "Fn-Ctrl-F3" if the F3 button is already assigned. Example in the screenshot: