The Lorax

When Ted visits the Once-ler for the second time and dives to the ground to avoid being launched by the sledgehammer as happened the first time, he stands up and his goggles are around his neck but hanging behind him.

The scene then switches to the Once-ler and then back to Ted, and his goggles are still around his neck but now hanging in front of him.

The second time Ted goes to see the Once-ler, he accelerates his scooter using the left handle; in the rest of the movie, the accelerator is in the (usual) right-hand handle.

When the family is playing a scrabble type game, Grandma has the letters LORXBRA, later in the movie she has the letters LRXBRA without playing her turn.

Just after Ted kisses the cereal box, a juice carton is on the table.

When Ted walks away from the table and is stopped by his mom, the carton is gone.

When Ted's mother escapes in her car, you can see the doll in the back seat.

After that it disappears during the whole chase sequence, then appears again when she stops.

During the "How Bad Can I Be" song it is seen that the Once' Ler has his sunglasses on when he adds the Truffula tree to his shirt, and a few shots later he is shown putting his sunglasses on.

After O'Hare is done telling Ted to never leave the city again, he gets in his car.

When he gets in his car is on one side of the tunnel, and when he drives away, it's on the other side.