Hrm, if it is just about making the DB File available elsewhere you can create a link to another location from within your OS. From that location a dropbox account could access the file to synch with your other machines.
That way you can effectively relocate your database. Check this post out.
http://forums.wolflair.com/showthread.php?t=51227
PS: I wanted to add that this is not a synch mechanism like it's available from LW cloud service - which gives you more features like player sharing and easier synching between your RW machines for your realms. With the info above you can only make a whole DB file available at several locations at once on file level.