Hey Seatbelt: Thanks for the post. I have been curious myself! I was just asked to engage in a 20 minute skype interview as well. I'm Comp Lit, but I think all Humanities are tending toward this interview process a bit more. They complimented my writing, said they enjoyed reading me, but wanted to know more about me. Mine is scheduled for a couple weeks from now and it is my general impression that you can't learn a ton from 20 minutes, so clearly they think you are a qualified applicant prior to this conversation. My guess is that they use the call to gauge professionalism, ability to think on your feet a bit, and motivation/sincerity. Of course, I am not an expert, and I would be curious to hear about others' experiences!!