Not surprisingly, Clash of the Titans won the weekend box office with a pretty decent showing of $61 million, fueled, in part, by the fact that a 3D version of the film was available alongside your standard 2D version. However, what you may or may not already know about the 3D featured in Titans is that it was added to the film after the fact, once Avatar made a killing at the box office. Considered by many to be a rush job (because the decision to convert was made only a couple months before), Warner Bros. still went through with the conversion, announcing they'd also be converting some other big 2010 films, like Harry Potter and the Deathly Hallows: Part 1.