In a TV show called Mysteries at the Museum I always enjoy looking for the mistakes they make in prop placement. They must not have a large budget for props and use whatever they can get. In a number of episodes they did a story about World War II and the actors playing the soldiers are carrying guns from WWI all the way up to the Vietnam era. That's not the best mistake though. In an episode that is set in the late 1890's a scientist is wearing a G-Shock. Pretty fun stuff.