This is a neat site I sometimes visit because it often has interest tips to make gardening in a small area more productive. it may be of more use to us living in urban and semi urban areas with small gardens.
http://www.verticalveg.org.uk/
I can see this good for city slickers ......and country folk, if you grow in tiers start with the low growing plants at the bottom , if you grow runner beans in this way go no higher than 3 ft , make a cain canopy for them to hang off 8ft up and 4ft across if you have room.
Put up 6 x 8 foot sections of drain pipe on a wall last year, kept us in lettuce & radishes for 2 months.
Bloody great idea UKS thanks