Plus, the iPad has a stylus that ships with every user. Multiple, in fact.
Dan Bricklin was working on something like this for the iPhone, and it'd be a natural fit for the iPad. http://danbricklin.com/log/2009_12_05.htm#notetaker
I also look at my dad's fingers, which have enough thickness that he can't comfortably press buttons on smaller devices. I have girlish hands :) so I can manage it, but really ... you're actually implying that we should throw away hundreds of years of using a pen?
I really don't see why we are arguing here.