Soldiers Memorial is a World War I museum built during the Depression and so neglected that the elevators don't work. It is situated on Chestnut Street in downtown St. Louis, however, which is low-traffic yet double the width of other downtown streets, which means a movie company can show a rented helicopter landing in the middle of downtown without messing up local traffic too much.

Elizabeth and Kayley's house and Eric's apartment were both filmed in the same house.

About three minutes into the film you can see Windows Media Player playing the animation of starting the experiment.

The oddly shaped building used as the lab, is the Planetarium which is part of the St Louis Science Center museum. It is one of St Louis' most unique and iconic landmarks.