Television has never gotten much respect, particularly from the folks who appear on television. Groucho Marx perhaps said it best. He summed up TV as “terrible vaudeville,” even as he was cashing his checks for hosting “You Bet Your Life.”

The purpose of television, or any dramatic art, is to convince the audience to believe that what they are watching is “real,” for at least 30 minutes or so. Occasionally, this means asking the audience to wink at its own suspension of disbelief by poking fun at what seems fake, lame or unreal about other shows.

“Seinfeld” did this rather brilliantly when the characters helped create their own NBC show “about nothing,” and we got to laugh at how wrong the “fake” Jerry, Elaine, George and Kramer looked on the doomed sitcom pilot.

Tonight, the ‘tween programming hit “iCarly” (7 p.m., Nickelodeon) gets into the act with “iCarly Saves TV.” Carly (Miranda Cosgrove) and her pals Sam (Jeannette McCurdy) and Freddie (Nathan Kress) are having fun with their homemade Web show until a network executive tries to turn it into a television series for kids.

All of a sudden, Freddie finds himself in a lowly producer position. Carly gets a house band and meets a talented new friend, Harper (Leon Thomas, “The Lion King”). The insufferably clueless network floods Carly with research from focus groups and tries to change everything that was fun and spontaneous about the “iCarly” Web show.

¢ “THS Investigates: Vegas Winners & Losers” (7 p.m., E!) takes a little of the luster off the fun reputation of the gaming capital. It offers profiles of card sharks, card counters and geniuses who tried to beat the system. It also takes a rather frank look at gambling addiction and those who would rather rob banks than give up their “last” chance to win it all back.

¢ William Shatner (“Star Trek,” “Boston Legal”) will narrate a 17-part series about extraordinary animals, beginning tonight with “Pachyderm Picasso” (8:30 p.m., Animal Planet) a profile of Hong, a 6-year-old Asian elephant who uses her trunk to create images on canvas with a paintbrush. Future Friday-night installments will showcase an orangutan with an extensive vocabulary and a sea lion that demonstrates an ability to grasp logic, once considered a uniquely human trait.

Tonight’s other highlights

¢ Harrison Ford and Josh Hartnett partner up in the 2003 buddy-cop drama “Hollywood Homicide” (7 p.m., Fox).

¢ Don’s team tries to outwit Megan’s kidnapper on a two-part repeat of “Numb3rs” (8 p.m., CBS).

¢ Zaphod leads a major defection from the Whiskers to the Aztec clan on “Meerkat Manor: The Next Generation” (8 p.m., Animal Planet).

¢ A rescue dog that never barked at the pound finds his voice and much more on “The Dog Whisperer” (8 p.m., National Geographic).

¢ Keira Knightley stars in the 2005 adaptation of “Pride & Prejudice” (8 p.m., Oxygen).

¢ Scheduled on “20/20” (9 p.m., ABC): Indian parents of a baby born with eight limbs want a normal upbringing for their child, despite the fact that some worship her as divine; two fathers meet while searching for their missing daughters.

¢ The rebel Cylons stage a hostage crisis to force the “Final Five” out of hiding on “Battlestar Galactica” (9 p.m., Sci Fi).