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. ...