AMES, Iowa – The sign sits propped on a wooden chair, inviting all comers: "Ask an Atheist."

Whenever a student gets within a few feet, Anastasia Bodnar waves and smiles, trying to make a good first impression before eyes drift down to a word many Americans rank down there with "socialist."

Bodnar is the happy face of atheism at Iowa State University. Once a week at this booth at a campus community center, the PhD student who spends most of her time researching the nutritional traits of corn takes questions and occasional abuse while trying to raise the profile of religious skepticism.

"A lot of people on campus either don't know we exist or are afraid of us or hate us," says Bodnar, president of the ISU Atheist and Agnostic Society. "People assume we're rabble-rousing, when we're one of the gentlest groups on campus."

As the stigma of atheism has diminished, campus atheists and agnostics are coming out of the closet, fueling a sharp rise in the number of clubs like the 10-year-old group at Iowa State.

Campus affiliates of the Secular Student Alliance, a sort of Godless Campus Crusade for Christ, have multiplied from 80 in 2007 to 100 in 2008 and 174 this fall, providing the atheist movement new training grounds for future leaders. In another sign of growing acceptance, at least three universities, including Harvard, now have humanist chaplains meeting the needs of the not-so-spiritual.