Tachyons
Things are moving swiftly forward in the time-travel department, with Tachyons currently providing the most likely mechanism. Traveling faster than light could in theory allow you to travel forwards and look back to see yourself in the 'past', but if these particles were proved to be actual objects, then they could in theory be manipulated.
Shoddy TV show Journeyman revolved vaguely around the theory, but Enitech labs seem to be currently leading the field. Check their videos for more info...
26th Mar 2008 - Tumblr