Billy Crystal has warned tech-savvy ticket holders of his upcoming comedy show "700 Sundays" to leave their cell phones at home - because he's tired of audience members 'tweeting' while he's onstage.

The 61-year-old actor/comedian is baffled by the sweeping popularity of social networking websites like Twitter.com, where members write up-to-the-minute updates on their thoughts and whereabouts.

The craze has made Crystal anxious to revive the Broadway show on his upcoming U.S. tour because he's convinced rude audiences will pay more attention to their mobile devices than his act.

He says, "I used to complain about the cell phones. Now they do everything, twittering, whatever it is, you're supposed to just come and watch... and then we had people pirating the show, which is a federal (offense)... It's kind of creepy. Please don't do this."

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Image © Chris Hatcher / PR Photos

(This news article provided by World Entertainment News Network)