We just started to use this little gem of a program with FCP and love it. Quite frequently, an editor will need to take a scene on location or home for the weekend and this program is great for this purpose. After creating an XML of a sequence, all you do is import it into Media Mover and it will move all used media onto a specified drive WHILE CREATING THE SAME FILE STRUCTURE AS THE ORIGINAL MEDIA. This is great as all the editor needs to do is send back the project file that he altered, and no relinking is necessary. It knows if a folder has been created previously, and if the media already exists there, it's smart enough not to move the files again.
We wish it would do the whole project and not just a single sequence, but it's pretty great.
http://www.automaticduck.com/products/mc/