Raspberry Pi GPIO Pinout Guide
I often find myself consulting a page or graphic for a particular pinout, be it WiringPi's pin numbering system, which pins are UART and I2C or a myriad of other functions, there's never really been one clear and concise place to consult for a particular pin function.
I decided to try and solve this in two ways. The first is my new, interactive pinout micro-site: http://pi.gadgetoid.com/pinout. This is targeted at modern browser/tablets and provides not only the basic pinout, but descriptions of the various different functions, overlays to show you different pinouts and more. Give it a try!
The second, is to borrow a good old fashioned paper trick that's been floating around the internet, one I have mentioned before; a paper pin overlay!
WiringPi's unique pin assignment scheme demands a unique overlay, so without further ado here you go:
It looks good printed out, although my printer leaves much to be desired. I chose coloured bars to clearly highlight the Power/Ground and separate them from the pin functions.