This module implements a binding to Google's CityHash family of hashing functions. You can find more information here: http://code.google.com/p/cityhash/. It implements both the 64-bit and 128-bit interfaces.
Note that CityHash is designed to work on architectures where unaligned reads do not have a large penalty. In practice it is only used at Google on little-endian Intel/AMD CPUs it seems, and has not been tested on big-endian architectures.