Jay Leno and Anti-Helium

Jay Leno inhales "anti-helium"... Hilarious!
Because the sulfur hexafluoride gas has a high density (over five times denser than air), it can be poured into open containers, like beakers and fishtanks. Moreover, light objects, e.g. ship-like vessels made out of light wood or aluminium foil containing air inside, can float on the gas. Another effect is the gas' ability to alter vocal sound waves. The gas can be breathed in a small, safe amount and cause the breather's voice to sound very deep. This, too, is due to the gas' density.

An ADMIN WORD OF CAUTION .... that although funny.... breathing in helium can in fact KILL YOU!.... too much of it will definitely kill you!

As it starves the lungs of oxygen much faster than you think!, which isnt a good thing we need oxygen ;)

from post on the net on a medical forum ..

It can be DANGEROUS!. Breathing in pure helium deprives the body of oxygen, as if you were holding your breath. If you couldn't breathe at all, you'd start to die in minutes—as soon as your body exhausted the supply of oxygen stored in the blood. But helium speeds up this process: When the gas fills your lungs, it creates a diffusion gradient that washes out the oxygen. In other words, each breath of helium you take sucks more oxygen out of your system. After inhaling helium, the body's oxygen level can plummet to a hazardous level in a matter of seconds.