This is the gag that I've been doing at the end of my show- it's different every time because I'm working it with local guys. But these guys had to be the best so far- with no rehearsal they pulled off the "heckling barbershoppers" routine. And their singing was great too. Have a look.
Tom Shillue's book "Mean Dads...." got a nice plug on "The Five" in the "One More Thing" segment from Dana Perino & Greg Gutfeld.