Nonlocal measurements and the early days of quantum teleportation

The idea of quantum teleportation emerged from a day of discussion, following an insightful question posed by Charles Bennett at the end of a seminar I gave at the Université de Montréal in 1992. The seminar was about research I had done with Asher Peres, in which we imagined trying to get as much information as possible from measurements on a pair of spatially separated particles. Here I recall some of this history, beginning with that two-particle problem. The evidence suggested that, even when the two particles were not entangled, it could happen that the optimal measurement was a joint measurement that could not be implemented by any sequence of local operations and classical communication.