The physical home button is gone, replaced by a virtual one with haptic feedback of its own. (tomsguide.com)
Here also, the warning is most often an audible tone, but General Motors has made very interesting use of haptic feedback with its Safety Seat Alert, which vibrates the seat to grab your attention. (cnet.com)
Amazon originally filed Patent 2750759 in 2010 for Haptic feedback for inclusion in some of their e-readers. (goodereader.com)