Most recent movies contain errors or "Movie Goofs" as they are called.
Below is a small list of those movie errors found in some recent titles:

Lord of the Rings
The Return of the King

Near the beginning of the film as the camera flies towards Rohan you can see the smoke pouring back into the chimneys rather than out of them.
The bloody cut on Frodo's right cheek switched to his left cheek when Sam is giving his "We must go on" speech (flopped shot).
At the very beginning of the film, the One Ring goes from muddy to shiny several times between shots. Ofcourse, one could see this as the magic of the ring ... *grin*

The Two Towers

At times the character Gimli is as tall as Aragorn's shoulders. At other times, he is much shorter. Dwarves can grow you know ...
Aragorn's beard repeatedly changes length between shots in King Theoden's hall.
Legolas' eyes are brown for the majority of the battle of Helm's Deep, instead of their customary blue. It has been pointed out that elves' eyes change color with their mood. However, a story is reported that, in fact, this particular color change came about when Orlando Bloom's blue contact lenses were forgotten during some of the shooting for this sequence.

The Fellowship of the Ring

When the Black Rider comes into shot while the hobbits are hiding under the tree-roots, he appears on the left-hand side of the tree without first being visible on the right-hand side (though it has been claimed that this is intentional).
In the final fight between Aragorn and the chief Uruk Hai, Aragorn is thrown against a tree and we see his sword fall from his hand. The next shot shows the Uruk Hai throw his shield pinning Aragorn to the tree and again we see his sword fall from his hand.

The Last Samurai

When Nathan walks into Taka's house after his first round about town since his capture, Taka cleans up after him because he has walked in with muddy shoes. The shot before this showing him walking in the door clearly shows clean shoes.

Could Mountain

In the scene where Ruby and Ada are looking at the stars, you can see an airplane flash among the stars. There were no airplanes in 1864.
When Ada and Ruby stargaze, Ruby identifies Orion. However, Orion is nowhere in that part of the sky.

Finding Nemo

Nigel, the Pelican, is a Brown Pelican, scientifically known as Pelecanus Occidentalis. The movie is set in Australia, where there are no Brown Pelicans, instead there is the Australian Pelican, scientifically known as Pelecanus Conspicillatus. Both birds look quite different.
Marlin and Dory are advised to swim to the back of the whale's throat and then are blown out of the whale's blowhole. This is not physically possible as whales mouths and digestive systems are not connected to their respiratory system and blowhole.
Coral should be bigger than Marlin. Female clownfish are always bigger than their mates (often twice as big).

The Matrix
Reloaded

When Trinity is driving down the freeway, the bullet holes in the right side of the car are not there on several occasions when the car comes into view from behind other vehicles.
When Trinity is driving on the freeway, her door is locked when seen from inside, but unlocked in exterior shots.
During the car chase, the twins shoot out most of the windows in the car that Trinity and Morpheus are driving in. But when seen from the inside of the car, the windows are intact and there is no shattered glass to be seen.
After one of the agents rips the roof off the car on the expressway, there are some shots that show the interior of the vehicle still dark as if the roof was still intact.
When Trinity is disabling the power grid, the computer terminal indicates that she is disabling 27 power nodes, numbers 21-48. That's actually 28 nodes.

Star Wars: Episode II - Attack of the Clones

When Obi Wan sends the message for help to Anakin and Amidala, Amidala presses a red button in order to transmit the message to the Jedi council. A minute later she presses the same red button in order to view a map of a galaxy, without first doing anything which might be expected to change the function of the button.
When Obi-Wan throws his blue lightsaber at Anakin, he catches it with his left hand while holding his green lightsaber in his right hand. In the next shot, when Anakin is fighting with Dooku, the lightsabers have switched hands.