Stylus ?
The whole point here is that to use the iphone you do not NEED a stylus, you could use one if you wanted. It is much easier to draw with a stylus, for example, than with your finger.
There are plenty of stylus models for iOS devices.
http://www.theverge.com/2012/4/10/2925937/best-stylus-ipad-review
I assume the ipad they will be bringing out will have a stylus, however, it will accept your finger input as well - and that is the whole point. Back then, a stylus was the only thing you could use on other devices, well, maybe you could manage with your fingernail, but that was hard.