It would be good if Dropbox had a feature where your space could be used as a virtual drive. So, as opposed to files and folders that you create (eg using Word or Explorer) and place on your Dropbox being created as local copies initially, and then you having to mark them as On Line Only for smart sync to remove them from your HDD and add them to your Dropbox, instead these files just automatically go to your online space.
I realise that if you create files and folders using the desktop app that this will happen automatically anyway, but I don;t want to use the app as I find it clumsy - I just want to create and edit files on a normal daily basis but have everything stored online.