1. In the last scene where Edward and Bella are sitting in the sunny field, Edward is not sparkling.
2. The Cullens are watching a news report about the violence in Seattle. It is night time in the report, and the reporter says "this is CNN live.". Cut to the Cullens watching the newscast and it is daylight out. Forks and Seattle are both on the Washington coast, it could not be night in one place and day in the other.
3. Spoiler! When Victoria's head is popped off by Edward who has killed her, her eyes are open. Seconds later, from another angle, her eyes are closed.
4. Just like in New Moon, Bella's scar from James biting her is on the wrong side of her arm.
5. When Bella's talking to her dad on the sofa early in the movie, watch her right ear. Sometimes there's hair covering it, sometimes it's clear, and sometimes there's a chunk of hair hanging in front of it.