I think Boskke's idea and implementation is amazing. They save space and water. Here is what they say about the Sky Planter on their website:
"Normal potted plants lose water through evaporation and drainage. The BOSKKE Sky Planter’s unique reservoir feeds water gradually to the plant’s roots."
The Sky Planter can be both used indoors and outdoors since it does not loose any water.
Its just as simple as their slogan on their website :"Turn gardening on its head".
via ETSY Blog