Cell phone company Nokia has issued a patent for a material that could be attached to human skin and would vibrate to alert the wearer of an incoming call or text message.
A patent application filed by Nokia last September would create, "a material attachable to skin, the material capable of detecting a magnetic field and transferring a perceivable stimulus to the skin, wherein the perceivable stimulus relates to the magnetic field."
In other words, it would be an attachable tattoo that would vibrate in response to a signal from an incoming phone call or text message.
How it works:
The ink material would first be exposed to high temperatures to demagnetize it. Then the tattoo would be applied. You'll apparently be able to choose the actual image you want as the tattoo. The procedure would be similar to that of getting a 'normal' tattoo.