I couldn't find such an original wallpaper, so I just created the wallpaper of my favorite keyboard key myself.
OS X users should know best what that icon represents: On Macintosh' operating system you use the ⌘-key (command- or apple-Key — the apple-key was removed from newer machines) just like the ctrl-key (Control-Key) on Windows or Linux machines. For further informations visit Wikipedias ⌘-page
You can use this wallpaper for free. You can also distribute this art as well but only under my name! And it would be great, when you tell me so
This is a 2880x1880 png image, ready for macs with retina display. So this may look downscaled like a bunch of ... dunno but not beautiful on normal displays ^^. If you like that image, I'll upload it in other versions/resolutions. Just ask for it