I am no expert when it comes to this stuff, but I think everything in the U.S. gets broadcast in 720. I was watching a friends 46 inch 1080p and it doesn't seem progressive to me. I think the uprezzing does this. So when I watch a 720p, broadcast on HBO or whatever it looks better. The 1080i (uprezzed) has that ultra real look. Maybe she needs to change something on the tv. Does this make sense.
No, most stuff in the US is broadcast at 1080i.
Your friend may have a 120Hz TV which makes movies look like live video. It's horrible.