When the Fellowship of the Ring was shown in theatres originally, in the scene where Sam and Frodo are in the Cornfield by the scarecrow, a car is visible in the far background. It was removed for the home video release, and Extended Edition.
Theres a bunch more funny ones like that for LOTR. But I have to agree with Oddguy I dont like to know too much for films such as LOTR, because you wish that they could be real.
