After receiving a lot of files with the dreaded ".docx" filename extension, I discovered that Microsoft has a converter available for OSX that transforms these Windows Office 2007 files into Mac Office 2004 format. It's not perfect (it's in beta right now) and doesn't work on everything, but worth having available. You can get it here. At the bottom of the screen, in the bottom-right-most window, scroll down to the "English (.dmg)" file. Download that, double-click it, and install the application, and then drag-and-drop files onto it to convert them. You can also convert a batch of files at one time using the menu commands.