Madelman has created WordLeaker, a tool which display hidden information as well as revision logs in Microsoft Word documents. Although seems that it is not compiled in, WordLeaker can also be found in as plug-in in libextractor, a library to extra metadata and similar information from various types of file.
For me, the interesting thing is because WordLeaker uses POLE , a portable and lightweight C++ library to read Microsoft OLE Compound Document (used also in some KOffice filters), which is one of my dirty hacks.