re:
Yep... Settings > touch is the spot...
BTW if you go to Settings > ringtones + sounds and toggle Vibration to "Off" in that spot, the nav bar key vibration is very minimal so you get subtle feedback without it being a huge jarring vibration.... That's how I set mine On in Touch but Off for ringtones + sounds.
I like to know I hit the nav key and it is the ONLY time I'll let my phone vibrate at me. Otherwise I can't stand it.