ObiJohnKenobi
iPF Noob
And, of course the big one, you must have an iPhone. Not everyone does.
You're right. It's funny, I don't ever imagine having one without the other. My iPhone and iPad to me are like one device, each extending the functionality and utility of the other.
You make good points. I haven't had a reason yet to need the GPS on my iPad myself, but I hadn't thought much about the battery drain on my iPhone.