While going without a stylus may seem the fashionable thing to do, the sad truth is that a stylus was more convenient and faster. It also made input more error free as compared to finger pushing. Perhaps its because you feel so comfortable with the iPhone that it invites you to use it like a PC rather than a phone. Whatever the case, the onscreen keyboard could certainly do with some major improvements.
Haptic feedback can definitely be one solution. Researchers are using tiny vibrations to imitate the feel of a button when a user touches the keypad. The user will be able to feel the edges of each key so will be able to identify where each key is without checking visually.
Compared to a standard keyboard, touchscreen keypads were less accurate in terms of text input. Without being able to identify through touch when a key had been selected there was a significant increase in errors made.
As users run their fingers over the keypad a wave of vibration is triggered signifying a smooth rounded button. When the key is selected and released different vibration patterns give the user the feel of a key snapping back into place.
It does sound like a major battery sucker and perhaps the idea of constant vibration doesnt sound as good once you get used to it. I would rather much prefer I can be able to feel the buttons on screen just like a real keyboard instead of having the whole thing vibrate.
If you still want to have a go on it, get some more details here.