Media controls in chrome for Mac Now Spotify is useless I've shifted Grooveshark, however there's a distinct lack of being able to use the media controls at the top of the keyboard to control it.

Is there an extension or (non-web)app to enable this? Grooveshark responds to space, ctrl+arrow, for play and skip to next/prev track, but only when focused. I'd like to remap these to the media controls, and if possible not have to have focus on Chrome and the grooveshark tab.
If you use the desktop client for OS X grooveshark says they have enabled keyboard shortcuts: 


  http://wanderr.com/jay/keyboard-shortcuts-for-grooveshark-desktop/2010/06/05/


But if you want to use the web player, it looks like it might be a lost unless you use Firefox for which there is an addon named keySharky: 


  https://addons.mozilla.org/en-US/firefox/addon/keysharky/