Import Objects - FBX Quicktime Viewer
Apple Quicktime Media Player has a plugin that enables a user to view an FBX file in a 3D environment.
You can view the instructions and download all the stuff for it here: http://udn.epicgames.com/Three/DevelopmentKitGemsViewingFBXWithQuickTime.html
This is really useful if you are modelling and want to see what it looks like before you import it into Muvizu, in case you think you may need to change something or tweak parts of your model. The controls are quite limited, but if you want to just quickly view what your model looks like before you start importing it to Muvizu, this can be a really useful little tool to have.
Once you download and install Quicktime and then the FBX viewer plugin, simply go to File > Open a file, then at the bottom right drop down menu, choose 'All files (*.*)' and now select your FBX file to view. After a few seconds, it should appear in a new window.