Stylish, sturdy plastic housing.
If one owner of 512MB RAM version of the PIs, you can fix it through the existing holes on the bottom of the housing. However, the housing is also suitable for the PI with 256MB RAM, since this will be held with minimum clearance from the housing walls in position (the 256MB RAM version of the PIs has not the holes in the circuit board). Since the housing are screwed together by hand must daruas arise about 5 to 10 minutes crafting fun until the PI is firmly seated in the housing.
My USB cable was a bit too wide for the opening in the housing, but I've also never seen any other cable, which is as wide as mine.