In answer to Chrono and Jimmy, time travel into the future is not just a possibility, but occurs whenever one body moves with a velocity wrt another. It was described by Einstein and is a consequence of the speed of light being constant for all observers. It is only really noticeable at high velocities (ie close to c)
When you fly to New York from London you actually travel about a billionth of a second into the future! This has been measured with Atomic clocks and agrees with Einstein's predictions.