Seven years ago, a filmmaker from Northern Ireland by the name of George Clarke claimed that he had discovered evidence for time travel in the DVD extras of The Circus, a Charlie Chaplin movie released in 1928.
The clip he uploaded to YouTube - taken from a video of the film's premiere in Los Angeles - purports to show a woman speaking into a small, black device held up to the side of her head like one would a mobile phone.
How and to whom she would have been communicating with is anyone's guess. Needless to say, they didn't have any service carriers in the 1920s, and even if they did, this woman, whomever she was, would have been the only person to actually own a mobile.
It also seems slightly odd that she should have used the device so brazenly in such a public setting. This is perhaps a sign that, at some point in the future, time travel is no longer the preserve of shadowy government agencies but instead completely open to any member of the general public with enough money. A terrifying thought.