@apreshill When Steve Bedrick taught map - reduce, he brought in a huge number of note cards to alphabetize, handed some of the stack to several people and told them to start sorting. When they were done sorting their pile, they delivered it to someone else who could quickly slot the sorted second pile into the already sorted pile they had. In that way, a very large number of cards could be sorted by hand much faster.

Not sure if this fits the bill but it sure helped me.