[xowl]

Here is something slightly different. It's an mp3 of 2 seconds of silence.

I set my phone to use this as the default ring and set it to ring+vibrate. That way I can assign an audible ringtone to contacts I want to always notice and let everyone else take their chances on me noticing the vibrate in time to answer. I originally created it because my gf was complaining that I didn't notice when she called.

You could also use it to remove the ring from one person if you have a normal ring tone set as default.