The fashionable e-Volveâ„¢ Gadget Shoulder Holster is a new “carry all” shoulder holster that allows you to get all of your personal electronic gadgets off your belt, out of your pockets and into a comfortable shoulder holster.
— Concealed Dork Permit: The Gadget Holster – Geekologie

I need one.  I have have this on one side and my gun on the other.  People will think that I am badass.