Effective in 60 days, cell phones and pagers are banned in Broadway theaters. This article doesn't give too many details but I assume the fine is levied if they catch you talking on one or if yours goes off. I'd be interested in knowing if this applies to silent pagers or the use of cell phones during intermission.
Like all of you, I've always been annoyed when some audience member's cell phone went off during a performance — and I was especially mortified once when it was mine. Two years ago, while seeing Follies in New York, I dutifully turned off my phone before the show started but apparently, I accidentally bumped its "on" button and turned it back on. At a key dramatic moment in the second act, it rang — and I thought everyone for six rows around was going to drag me into the aisle and throttle me. Which would have been more than justified.
I didn't answer it. Instead, I ripped the back off and yanked the battery out. Since then, if I have my cell phone with me at a show, I always remove the battery. Better that than having someone in the audience remove part of my insides.