You would think this would be easy, seeing the options in the sound settings menu....but I have yet to find the right solution, to only vibrate for any kind of alert. Text messages, emails, app notifications, all I want is for them to vibrate, but this won't work on my iphone 4s from Verizon. I have the ringer turned off, on the side. And I keep sliding the vibrate on and off on the settings menu to no avail. Any suggestions?