I'm interested! A high school friend of mine went to a university where a cappella rush was huge. You got into a group not just on the quality of your voice, but also on your personality and how well you fit in with the group.
I sang with an a cappella group in college, but the process of joining placed a lot of emphasis on auditioning rather than on whether you "clicked" with the group. (Which, fortunately, I did.)
What voice do you sing? I'm a sopralto