pdfix
Simple command-line tool for propertly rearranging PDF files scanned with printer that doesn't have duplex capabilities.
Problem: a printer without duplex capabilities requires that all of one side of a stack of papers be ran, and then all of the other side be ran. For a six page document, the output becomes:
[page 1] [page 3] [page 5] [page 6] [page 4] [page 2]
This utility will rearrange them to the proper order.
Usage
pdfix example.pdf will create a file fixed-example.pdf in the proper format.