The Moni Shelf has to be one of the simplest, yet most versatile wall shelf solutions I've seen. Unlike most shelves, you can literally arrange it into a variety of configurations that can add a definite touch of style to any room in your house.
Designed by Carme Pinós Studio, the minimalist shelf consists of a single rectangular piece of steel that's folded into a three-sided panel. Basically, you mount each panel individually, arranging several of them into any configuration you want. With a little creativity and imagination, you can turn these into fancy-looking wall decoration on top of being functional shelves for holding all your mess.
The Moni Shelf is made from 2mm-thick steel and measures 38 x 16 cm (length x height). It comes in three depths -- 20, 35 and 30 centimeters, so you can choose one that's sized just right to accommodate your stash. In the pictures, the shelf is mounted either with the folded sides acting as bookends or the folded sides acting as legs. From what we can tell, you should be able to mount this vertically, as well, with the folded sides acting as the shelving surfaces.
You can get the Moni Shelf directly from the designer's Objects website, priced at €29.75, €31.75 and €33.75, depending on the size. It comes in either a varnished or dark gray coated finish.