SF Media Labs' "Joydick" is probably what you think it is: not safe for work in every which way. It's also "a wearable haptic device for controlling video gameplay based on realtime male masturbation."
Oh, science. What are we going to do with you? And by that, I mean what took you so long?
As one can see from the NSFW(!) video demonstration of the Joydick in action, the device attaches to one's ring-finger and man parts (the "Linus"), allowing for four degrees of movement and rapid fire button presses via hand-strokes. It's all about transcendence, according to its creators.
SF Media Labs' web site provides a list of the essential parts and programming required to make your own Joydick, should you be so inclined. Perhaps you can unseat our own Owen Good as the King of Stampede.
Or perhaps there's just a Wii joke in here that you're dying to get out.