I have a MacBook Pro, and a Windows XP Virtual machine, and use Eagle at work on another windows machine, The work machine and my mac are both sharing a Dropbox folder, (Alex Lang has instructions on how to install Eagle on Windows). (If you use Eagle 7.1.0 you can unlock it a bit using this file eagle-win-7.1.0.exe, and replace eagle.exe in the Eagle/Bin folder).
Open Eagle, and then in the menu Options > Directors
The Virtual box Virtual machine is set up that the entire Dropbox folder is a shared folder with it,
At this point it is a wise Idea to stop Eagle from updating, as you will want to keep all eagle editions at the same version number.
The slightly dodge copy of eagle will make making multiple sheets, and larger boards much easer than the previous multiple sheet method, With the official version of 7.1.0 you can still move components any sheet, and draw, and rename wires and nests (just cant add components).
Oh and the easy way to move things between sheets, click move, then use the group select tool, right click move group, and then hold down the shift key as you mouse over then additional sheet 😀