Unlike the beloved character, your nose does not grow longer when you lie, it actually heats-up instead. 

In new research that uses thermography to study the temperature of people's faces, a jump was found in the temperature around the nose and in the inner corner of the eye when someone was lying.

The researchers say that lying boots the activity in a certain area of our brains that is detected by the increase of temperature in certain regions of our body.  In addition to detecting lies, thermal cameras can also detect someone being drunk.

After subjects had been given 4 drinks, the researchers noticed that the nose and mouth areas were much warmer than the forehead area.   As for practical everyday uses for this thermography, that remains to be seen.  But, in the future, getting away with a lie could be much more difficult.