I've always heard that schools that generally only take students they can fund (NYU, GWU, etc.) tend to narrow the applicants down to a semi finalists list, interview them (via phone usually) to see how articulate/socially adroit they are and to get a feel of how well they can communicate their research goals, etc. and then meet a second time to make the final cuts.
Otherwise I feel that faculty will more likely call one of your LOR writers, especially if they're friends/conference buddies.