I don't see the need for a screen protector on the iphone and definitely not the ipad.
I have had an iphone for 2 years. I don't have a case or screen protector for it, and carry it around all the time in my jeans pocket. My iphone screen has no scratches on it, at least none that I can see without taking a magnifying glass to it. I think the screens are made to be almost scratch resistant.
I'm assuming the ipad screen is the same and since most people won't carry it around or abuse it as much as an iphone, I think its even less as risk for scratches.
Therefore, don't bother with a screen protector. The screen is extrememly durable and I doubt you will have any problems.