Player places block of sponge (configurable) on flat area, type /tent and hit block. That block will then change into small room with wool walls,torch, workbench, furnace, small chest and bed. And of course a door, so mobs can't get inside. If area is too small for the tent, nothing will happen and player will get message about it. This could be used as portable exploring station, so you can craft without being disturbed by mobs and quickly skip nights by safely using bed in the wild. If you destroy any of the generated tent blocks (surrounding wool, door, workbench, furnace, chest, bed or torch), it will drop no items from that block, but whole tent will be put back into sponge block. And of course all items in tent's chest will be dropped to the ground. What do you think?