If you have a garden you can make you such a tree pendant lamp: simply plant a tree, train and graft around a frame and harvest after a couple of years. Very simple.
;-))
Anyway I find it great, just as the chairs and everything else! :)
Thanks for the link, A.!
Links:
Tree Pendant Lamp (Hexagon Pendant Lamp)
=> you find the lamp in the diashow on top or you can scroll down to The Hexagon – The First Pendant Lamp