Video: Fred Armisen impersonates Ira Glass

Last weekend's episode of public radio's This American Life offered an unexpected treat: Throughout the ep, titled "Doppelgangers," comedian Fred Armisen sat with host Ira Glass and impersonated him while Glass squirmed.

Armisen's impression was uncanny, although at times Glass didn't seem so sure. ("Do I sound that nasal?" he asked. Armisen: "Maybe.")

The two discussed how Armisen developed the act...