when in mc just look at the bottom u see a line wich shows available space, for me it currently shows "29M (12%) of 228". and for example i see "sounds" folder is taking this space so i moved it to "/opt/share/sounds/" and made a link for it to "/usr/share/" where it should be, voila free space gained. i also did this to some other folders.... But if you do this i take no responsibility of your actions if you brick your device!!!