[boost] Units of data

Has anyone extended (even privately) Boost.Units to include support for units of data (bits, bytes, KB, MB, etc)? It seems like this would be a useful addition to Boost.Units. Assuming no, what is the minimum amount of work required to do this myself? There's not a lot of info in the docs on how to define new base units, although I've already begun looking over the source code to try to come up with something.