Sculpteo's iPhone Case Design Challenge

We're reviewing the winning entries to Sculpteo's iPhone Case Design Challenge and we like what we see. 
 
There are some very interesting designs, including the winner above: The String Case by FCPRS. It's quite startling to see how inventive designers can be given the constraints of an iPhone case. 
 
Strangely, the winning entry and some others cannot be purchased from Sculpteo, as they are marked: "This design can not be ordered"