And now it's time for another Geek Thoughts.
Here's why I think all Earth-bound attempts at time travel are doomed to failure: Unless the time travel also involves some sort of spatial component, the time traveler is going to reappear in empty space. The Earth is in motion. The solar system is in motion. The galaxy is in motion. The universe is in motion.
By the time you finish reading this sentence, the Earth will have moved far beyond where it was located at the beginning of the sentence. If you were to travel back in time (or forward in time) just one minute, what is it that would keep you tethered to the Earth as opposed to some absolute location in the universal scheme of things, an absolute location essentially in empty space? (Or, at the very least, in the middle of an ocean.)
I'm not saying that time travel is impossible — though I believe that's likely the case — I'm just saying that time travel is impractical, and isn't likely to produce anything other than a bunch of space flotsam.
Teleportation, on the other hand, might be practical. If it's instantaneous.