For urban dwellers who are short on space to grow things, there's a multitude of interesting designs that maximize every available inch -- like assemble-it-yourself, crowd-sourced windowfarms or compact hydroponic units that fit in the kitchen and elsewhere. For those who haven't got the patience to set up their own, say, windowfarm kit, there are these lovely "mini aqueduct" modular planters from designer Evan Gant, which also happen to be a 3D-printed item.
The simple spouted design allows for top-to-bottom trickle irrigation, with the bottom planter emptying out into a larger potted plant.
This modular mini planter system allows for the creation of a wide range of unique configurations. Water is shared through the system, flowing from the top planters into the bottom, saturating the soil of each plant along the way. These planters are perfect for air plants, succulents, or any small plant that requires little soil.
You can apparently get a set of 10 planters for US $75 over at Shapeways, which includes 3 double channel planters and 7 single channel planters. Individual planters are also available. Seems like an almost foolproof way to quickly get some green into a small living space.