Steal This: Waterwall Design

Take 50 used Voss Water Bottles (or any kind of glass container), add some decorative grass or flowers or whatever you choose, shelve them in a western-facing window, and you have a beautiful and green display. The water inside the bottles acts as thermal mass, absorbing and storing incoming heat and then releasing it after the sun has set. Cooling in the day, warming in the evening.

I love it! I wonder how long it would take if I use vodka bottles here at the house. More instructions on the shelving are available by clicking the link below.  (Source)