Who's On What Tonight? Your Guide to Late-Night TV (Wednesday, Oct. 3, 2012)

CONAN O'BRIEN: Butter's Jennifer Garner, The Expendables 2's Terry Crews, music group Tegan and Sara
DAVID LETTERMAN: 30 Rock's Tina Fey, sweater vest expert Rick Santorum, LP
JAY LENO: Up All Night's Christina Applegate, Olympian Apolo Anton Ohno, music group A Fine Frenzy
JIMMY KIMMEL: Parks and Recreation's Amy Poehler, Argo's Alan Arkin, music group Garbage
JIMMY FALLON: How I Met Your Mother's Martin Short, The Perks of Being a Wallflower's Logan Lerman, musician Morrisey
CRAIG FERGUSON: Whoa, it's Keanu Reeves, Dan Riskin

Guest lineups are subject to change.

SOURCE: The Late Night TV Page