The Less Lamp is a lamp that comes to you as a black sphere that does not even properly emit light. You then punch holes in it according to your own taste using a pickaxe to let the light in. A great customized product. Reminds me of one of my favorite items by Dutch design label Droog, the Do Hit. 

The Do hit is by Marijn van der Pol. The Do Hit is a simple sheet metal box. It comes with a hammer so you can shape it by hitting it. You can also pay extra and have Marijn do it for you. Both the Do Hit and Less Lamp are great and very active, very literal and very fun co-creation concepts and I'm still amazed that the Do Hit is from way back in 2000.