A simple low-cost natural way to provide water to plants, the Clayola was developed by Rami Halim based on ancient technique in North Africa using porous ceramic pots.  The Clayola can provide 20 literes (5 gallons) of water for 6 -8 plants for up to a month.  Check them out here.  

Artisanal clay pots from Egypt can water your plants for up to a month

View Slideshow Gardeners who travel will love these absorbent clay pots from Egypt. Modeled after the Olla, an ancient ceramic pot prevalent throughout North Africa, the small vessels are designed to water plants for weeks at a time-using nothing but gravity.