Ahh, but argon can also be used to alter the voice and we won't run out of that. You just sound more like Barry White than a smurf.
Personally, I find that funnier than sounding like a smurf

You might find Sulfur hexafluoride (SF6) to be more entertaining...
Plus you can have fun with it's properties - it's so dense you can float a paper boat ON THE GAS!

I must say however, I really wish people would stop wasting Helium, without it we are *really* screwed when it comes to certain scientific research (cryogenics, superconducting magnets, MRI scanners, etc.) . It's not just a fun party balloon gas, it's really important stuff with unique properties. And yet it's sold off at ridiculously low prices, and thus wasted at an incredible rate. Once it's gone,
IT'S GONE! Sure we can (could) make
small amounts with fusion reactors, but there is no way to produce 0.1% of the global usage, let alone enough to waste it as we do now. It takes a very long time for Helium to accumulate naturally, and fusion reactors will likely reuse most of the Helium they produce (breeder reactor or directly for fuel) - and even if they didn't , and
ALL the worlds energy was supplied via fusion reactors....it still would be
nowhere near current production of Helium. So it really is a finite resource...

A few of the more interesting properties of Helium (watch all in playlist):
http://www.youtube.com/playlist?list=PL442F47F12D99C4D2SS