Vertical farming

Some links on the concept and reality of veritcal farming in urban areas

http://www.youtube.com/watch?v=zkwbJJpeiVs&feature=related

http://www.youtube.com/watch?v=PaoCRNMot1E&feature=fvwrel

http://www.youtube.com/watch?v=MPvgkZhrWUA&feature=related

http://www.youtube.com/watch?v=hsIzkyWb7UE&feature=related