It drives me crazy when movies ignore advances in technology, like in Phone Booth, where Colin Farrell conducts his extramarital almost-affair in a phone booth instead of on a mobile with a bill-less, pre-paid cellular plan. When's the last time a New Yorker ever found a working pay phone anyway, 1995?
Cell phones actually play a big part in Collateral. Tom Cruise sends an email on his Sidekick, although sadly it's not as glamorous as Lindsay Lohan's Swarovski covered model.

And where does a hitman store the addresses and photos of his victims? In his PNY USB Flash drive, of course. The cell phone then gets its big, scene-stealing moment but I won't give anything away.
The phone then gets the starring role in the new Kim Basinger thriller, CELLULAR. The hilarious tagline is "When the signal dies, so does she." I'm glad she didn't call me, she'd be so dead since I never seem to get more than a single bar on my phone.
Next up, look for Cell Phone, by Chinese director Feng Xiaogang. In this comedy, a cheating husband's infidelities are discovered when he leaves behind his cell phone and his wife reads the text messages from his mistress. The movie was a huge hit in China, and apparently led to many spouses demanding access to all text messages. China's national cell provider released a statement, reassuring users that their account information was private.