Prince William & Harry Geek Out Over The Dark Knight

0426_prince_harry-charles_GettyPrince William and Prince Harry bow down to someone else other than the Queen ... the Dark Knight.

The Royal brothers -- along with pregnant Kate Middleton -- went batty acting like little kids checking out props from "The Dark Knight" trilogy at the opening of the new Warner Bros. Studios Leavesden in London on Friday.

Even heirs to the throne think Batman is cool.