I hope this isn't a stupid question. I know the iPad has a screen capable of displaying 720p, and I have seen people comment that they have put their own 720p videos on the device for viewing on the iPad. My question is, would it be worth it to put iTunes HD video on the iPad instead of the regular SD? Can you notice the difference? Just curious if anyone has done this. Obviously it would carry a bigger file size, but that's not really a concern.