(at around 1h 9 mins) When Will pulls the whip back, he cuts Amy's face. When she runs up to him, the cut is gone.
(at around 26 mins) When Hancock sits up, he has a bottle in his hand that he didn't have seconds earlier.
(at around 14 mins) You can see Devin Crittenden's character wearing a pair of yellow shorts with his legs shown. After Juney hit him with a guitar, it was obvious that they used a double, because the legs don't match.
(at around 46 mins) In one shot, the Enchanted Princess is holding the shoe-phone. The shot switches to the other people. When it switches back, the phone is gone. Later, Calvin is wearing it, without retrieving it.
(at around 57 mins) Calvin gets out of the Mach 5 1/2 and starts running towards the front of the car, but when the Enchanted Princess gets out of the car, he's behind her when she runs away.
(at around 42 mins) The "naked" Incredible Hulk is clearly wearing green-colored underwear.
(at around 4 mins) The website on Amy Winehouse's I-Book is 'FaceNook', but it is called 'FaceBook' in the dialogue.
(at around 56 mins) When the Princess is shooting Speed Racer over and over, the slide on her automatic pistol never moves, plus no spent casings are ever ejected.
(at around 57 mins) The sword on the statue that Amy is pinned under has a wide blunt tip that's obviously resting on her shoulder. She's not "pinned through to the floor" like Will says.
(at around 14 mins) Juney sings "I just sold the baby to the highest bidder on eBay," but the website she's on is called "Upay" not eBay.
(at around 1h 1 min) If the Crystal Skull is not placed on the altar, the entire world will end. With this in mind, Beowulf and Kung Fu Panda have no motivation for wanting to stop the main characters.