Perhaps a headset that induces signals into the brain that allows one to fully experience memories or live moments of someone else. Assuming bandwidth and storage are not an issue... There have been movies based on this idea. People could effectively live through other people and experience things that they would otherwise never be able to experience. There would probably be an underground market to acquire illegal experiences. People could also learn first hand how to do anything. People could in effect go anywhere. Maybe people could even experience first hand what it is like to be any animal assuming the interface could translate the signals.