From my hat full of stupid Mac tricks:
I use a lesser-known (and very old) program called Spark for defining most of the keyboard shortcuts on my system. I have a shortcut for every one of my most regularly-used applications, plus shortcuts for various AppleScripts, shell scripts, system functions, etc. I know there are more recent applications which do the same thing, but I’ve had everything set up in Spark for ages and it still works a treat. Seriously, if you want an application launcher, it’s worth checking out (and free). However, you can use this tip in any app which lets you assign a hotkey to an AppleScript (FastScripts, BetterTouchTool).
This is a companion discussion topic for the original entry at https://brettterpstra.com/2011/01/22/quick-tip-applescript-application-toggle