Theoretically the more we begin to map the brain and understand consciousness more and more, we begin to recognize that existence itself is basically perception. We think, therefore we are, in effect.
This poses an extremely interesting and enticing prospect, that our consciousness possesses 'savestates' in the same way (for example) waybackmachine archives the Internet. It could theoretically be possible to begin to map and understand these 'savestates' and perhaps even one day 'trigger' them within a subject.
If you were to do this, you would theoretically teleport a person's consciousness back to an earlier point in time, allowing for what is effectively time travel.