How do I stop the play/pause keyboard buttons from launching iTunes on Mountain Lion?
I searched everywhere for a clean solution. Many solutions that worked for Lion and below no longer worked for Mountain Lion. However, this works and it took me hours to find. Enjoy!

http://gavinroy.com/posts/disabling-default-itunes-launch-behavior-with.html

From the website:


  In a search for a non-hacky way to disable direct mappings to iTunes for the play/pause/next/previous buttons in the keyboard in OSX, I stumbled across the "Remote control daemon" (rcd). As it turns out, disabling the iTunes launch behavior for these keys is as easy as unloading rcd with the following command:


launchctl unload -w /System/Library/LaunchAgents/com.apple.rcd.plist