I need to stay away from this forum cuz all of you are just crazy.
I shoke my 64gig 3G and yes I hear it too. But this type of rattling is
inperceptable from regular usage. But, if you hold it nest to your year
and place your ear near the backside apple logo and shake it violently yes
you will hear something.. must like how one of the posters described as
a grain knocking against something.. but only when you shake it violently
and put your ear up against it. And you can only recreate this sound if
you use both hands and shake rapidly since the ipad has a decent heft.
If you only hold it using one hand, you can't hear anything really. There is
also no physical cluncking that you can feel through your hands when you
shake it.