Perhaps the most unusual element of "The Messengers'" promotion is the downloadable ringtones available for the target-market’s mobile phones. Participating wireless carriers are AT&T, Cingular, Sprint and T-Mobile.

There are two different ringtones, available for 99 cents apiece, but there's a twist. In keeping with the movie's theme that "there are some things only children can see and hear," the polyphonic ringtone technology can't be heard by users over the age of 25. The aim of this is to let teens and young adults keep their cellphones on at all times (e.g., during school) without getting caught. Some of us will have to take their word for it that the under-25 set can hear it!

Ultrasonic ringtone