Well personally I started running out of hot keys so I decided with a little help from Chris Maddox to change my caps lock key to active alfred.
The first thing you need to do is install PCKeyBoardHack so that you can remap specific keys. After installing the application and restarting your computer open system preferences and select PCKeyBoardHack under "Other". Now change caps lock key code to 110.
After this is finished you will need to install KeyRemap4MacBook so that you can change the caps lock key to something meaningful. Once this application is installed and you have restarted, open system preferences select KeyRemap4MacBook and open the For “PC Users” tab, followed by the “Change PC Application Key” now set your application key to the same hot key you use to open Alfred. In my case i overwrote spotlight to be be alfred so i selected “Application Key to Command_L + Space”
Once this is finished click “ReloadXML” in the upper right hand corner and now caps lock should open Alfred!