Just curious: For movies bought/rented off of iTunes, what are the respective resolutions (HD vs. standard)? I'm pretty sure the normal video is 720x480. Is HD video 1080p, or 720p? Is it worth the price difference? And also, if I were to make a purchase using iTunes gift cards, but one card didn't have enough, could I carry over the remaining cost to another iTunes gift card? (This is sorta irrelevant).