The perfectly named La Cabane Perchee is a French architectural firm devoted exclusively to the creation of treehouses. I can't think of a cooler job. They say: "Each is unique, in the spirit of its owner and of the tree it is nested in". One more reason to move to France!
Update: they won't break a single branch or drive a single nail into the tree during construction. Even better.
Just last week Chelsea wanted to live in a treehouse!