My office building is like a post-Apocalyptic scavenger society. When people don't need something anymore, they'll just stick it out in the hallway — desks, chairs, bookshelves, filing cabinets, boxes full of binders, computer parts, books...
And then people come by and sift through it, taking whatever they want. If it's not gone by the end of the week, maintenance personnel come by and cart it either to the trash or (for furniture) one of the loading docks, where it'll sit until someone comes looking for such an item.
It does make it kind of difficult to maneuver if offices on both sides of the hallway are cleaning house at once — but on the other hand, it makes getting rid of useless crap really easy.