Between me and my family, I think we could build a whole neighborhood worth of these plastic bottle greenhouse. This is a great way to up-cycle all of your old soda bottles knowing they are helping you grow your food instead of littering up the streets or in a landfill.
This DIY greenhouse is easy to build and over at nead.org.uk they have a great step by step tutorial all on one free PDF. You can download or print off, whichever is easier for you. I personally printed it off and left it on my husbands desk (sometimes you have to keep hinting to him before he gets it)