The iPhone wasn't actually busted, as disassembled or broken, but was used on the popular Discovery Channel program MythBusters where cohost Adam Savage used an iPhone's stopwatch feature (part of Apple's "Clock" app) to "bust" or "confirm" urban or popular myths (original idea Macenstein) (10/31/07 Trail Blazers episode).

(Update) It appears as if CBS currently has the corner on iPhone sightings. Do they only have one in the prop room or is each show allocated their own iPhone?

Sightings were also "Confirmed" on CBS's NCIS ("Leap of Faith" 10/23/07) where Jethro Gibbs (Mark Harmon) used an iPhone to take the picture of a Navy officer threatening to jump off a 10-story building and then e-mails the photo to Abbey (Pauley Perrette) in the lab for photo comparison and identification [on screen 3:39-4:09].

A not-so-"Probable" scenerio was also on CBS's Numb3rs (Episode 403 10/12/07) when Charlie Epps' (David Krumholtz) girlfriend Amita (Navi Rawat) is "busted" after she dropped her iPhone and had it returned by Charlie's dad Alan (Judd Hirsch) during a chess game on the University Campus with Dr. Larry Fleinhardt (Peter MacNicol) [on screen at ~16min].

Thanks to:
Reader dchoy
"Barney (Neil Partick Harris) on How I met Your Mother regularly uses an iPhone on the show." (CBS)

Reader Stefan
"I've seen Charlie (Charlie Sheen) using one in "Two and a half man" S05 E04 at a coffee shop to receive a call from his girl friend." (CBS)

Reader "Unregistered"
"Dan (Kevin McKidd), the main character in Journeyman, carries and uses an iPhone when he's in this time. When he's in the wayback, he uses an old Motorola flip phone that always seems to have an active account no matter when he shows up." (NBC)

Any other sightings "confirmed" or "busted", let us know what you think over in the comments and forums.