From www.visualnews.com comes this story about using plastic bottles filled with sand as bricks for building:
A surplus of empty plastic bottles is something that not only affects Africa, but the entire planet. In a small village in Nigeria, a solution has been applied to not only provide shelter in a poverty stricken country, but find a use for refuse. Packing sand into plastic bottles is a technique that started nine years ago in India, South and Central America. Named “bottle brick” technology, the compacted sand inside the bottles is almost 20 times stronger than bricks. The best part is that in a region that does not have much money to spend on building materials, the houses are estimated to cost 1/3 of a house made of concrete and bricks.
Adding to the appeal of the simple technology, the houses are ideal for the hot Nigerian climate because the bottle bricks buffer the house from the intense heat. Also, in a place known for violence, the houses are completely bullet proof. Bottles are mostly sourced from hotels, restaurants, homes and foreign embassies, so the 500 million bottles that are discarded each year in Nigeria alone are literally finding new homes instead of landfills or the ocean. The circular houses look cool too with the exposed round bottles producing a unique design.