If you follow the newest press on science, you've likely heard about the theoretical possibility of "cloaking" an object, so that it would be invisible to an external observes perception of time, effectively allowing it to move instantaneously to the observer, but not to the cloaked object.
It would seem that if this would be feasible, it would be the most likely means of exploration of space. With the time to travel to outside the system likely to remain beyond human capabilities due to the travel time involved, a cloaked robotic system could cloak, travel to the distant system, return, and assuming that exploration would require uncloaking, the only elapsed time back here on Earth, would be the time spent exploring. The robotic space craft would clearly need redundant systems, and built to last (sorry Ford if that a copyright), but this approach would circumvent the problems with humans traveling the same distance and time.
An article on the whole time cloaking can be found here: