Linkin Park now playing in your nearest masjid

Or it could be Metallica, or P. Ramlee, or whatever mp3 tunes that you have set for your ring tones.

C'mon, people.
If you have those ring tones, please switch your phones to silent mode if you don't want to switch the phone off. It is rather annoying, what with the fact that it is actually rude to have music in play while the Khatib is giving his sermon during Jumaat.

On the other hand, may I suggest that you discard your mp3 ring tones and stick to the normal, boring old standard ring tone. That is, if you're the kind of people who always forget to switch off your phones before entering surau or masjid.