After we wrote about making bookshelves out of black pipe, we stumbled on these images of black pipe closet fitting. We'd taken them a couple of months ago at our friends' newly renovated, about-to-be-moved-into, Brooklyn brownstone; there are no clothes hanging yet so you can really see the detail. We're thinking that the resources in the bookcase post - where to buy, and the basic how-to's - are about all you need to do this-cool-closet-treatment yourself. The black hangers turn the whole…