First it starts with the setup. At work I have an external monitor and keyboard. I keep my MBP to the right so I can use the touch pad here and there when I can't use the keyboard for certain things.
Here are some tips/programs/plugins I use:
1) Vim (not macvim) and screen - This dynamic duo is the greatest invention. I recommend it to anyone who has the time to learn. Once you do, you'll never go back.
2) Vimperator - Firefox plugin - This one has changed my browsing experience for the better. Once you learn all the commands you'll be flying through pages.
3) Remap your CAPSLOCK key to ESC - Once you start using vim and vimperator, the esc key becomes more useful. I remapped my CASPLOCK key to ESC so its quicker to reach. I used the program called PCKeyboardHack.
4) Learn your keyboard shortcuts.
6) Try to replace programs you use often with console versions. For example I dont use any gui programs to access databases. Diffs/text search/file searches are all done through command line.
7) Spotlight - I don't use Dock, sometimes I forget its even there. I would disable it if I could.
8) pbcopy - command line program that you can use to copy to your gui clipboard. Try piping contents of a file to it. Becomes very handy.
Most of my day I spend using Vimperator and Terminal. So it's easier for me to not have to use a mouse.