Here on Earth, it makes party balloons float, and men's voices sound like chipmunks. It also makes up large percentages of stars, including the sun, and is one of the gases that fills up the universe (believe it or not, it isn't a complete vacuum out there! Hydrogen and helium are everywhere (the atoms are just really far apart.)) So if suddenly there were no helium, the universe would have a lot less mass - kind of like a couch potato who stops eating at fast-food places suddenly looses a bunch of mass.
Most new helium atoms in the universe are formed inside stars, when the weight of the star causes two hydrogen atoms to smash into each other. Helium on earth usually has a different cause, though - it happens when radioactive elements decay... But even with all of the possible sources of helium (like, every star in the universe) the constant creation of the stuff doesn't make much of a difference, because there's already so much of it - and that's good, because even though stars make helium, they also destroy it (by turning it into other stuff).
You see, like I said before, the heat and pressure inside a star causes hydrogen to smash together and make helium; well as the star gets hotter and hotter, and the pressure builds, the helium starts to get smashed together, too, and becomes other atoms. And then those atoms are crushed together, and those are crushed together, etc... Bigger and bigger atoms come out of it all. And it all starts when two hydrogen atoms get together, and form one helium atom!
Before you know it, there are carbon atoms, and heavier carbon, and other stuff. All of the imaginable atoms you can think of can be made in a star - starting with hydrogen turning into helium in a very young star, to more complex atoms in older, hotter stars, all the way to heavy metals in supernovas. Pretty cool huh?
Helium has an important place in the universe, as we can see. And it also has an important place in cyberspace. It's kind of like we're all hydrogen atoms on our own - but then we're brought together, and boom!... helium. The more and more of us are brought together to one place, and before you know it, there are other things formed (like money!)
Ahh, yes. Helium has an important place in the universe.
I think I'll go talk like a chipmunk now.