Pop stars on talk television this week include Christina Aguilera as musical guest on the Late Show with David Letterman on Monday. Also on Monday, Mandy Moore will guest host MTV’s Total Request Live, while Backstreet Boys star Nick Carter stops by the show on Tuesday. Later Tuesday, Michelle Branch will perform on the Conan O’Brien show. On Thursday, *NSYNC star Justin Timberlake will stop by the Tonight Show with Jay Leno. Check your local listings for stations and times.