Intro: VideoGuide - Really Simple and Convenient Vertical Flower Garden
Step 1: Support Structure
Obtain a metal wire grid and mount it on a wall, so that the horizontal wires are facing away from the wall. You should find these basically in all larger 'home depot' stores in the garden fence section in the form of rectangular modules. However the ones intended for fences are usually so-so looking with hot zinc plating and thin wires, therefore it is much better to locate a store furnishings supplier and buy those heavy duty (thick wire) chrome plated grids used for display of clothes (they are made to be fitted with various hooks and shelves and should withstand much higher load).
Step 2: Containers
Obtain suitable containers, which you will use as planters. I was fortunate to find these great containers for about 50 cents each at IKEA when they were liquidating their stock of some garbage sorting system, there you will need to look around for something similar. What you really need is some overhanging edge, which you will be able to modify (I used a hot iron and an X-Acto knife) to create a "tongue" which you will be able to easily hook onto the metal grid.
Step 3: Planting
Since you are using closed containers (no bottom drainage hole + tray) you need to make sure that you don't overwater the plants as otherwise they will rot. To accomplish this, the bottom 1/4 - 1/3 should be filled with kermesite/gravelite etc. before you fill the rest of the pot with regular soil. Since you won't be able to easily see how much water there is actually in the pot, you should fit them with these simple floater level gauges, which will provide a quick visual indication of the actual water level and if the plant requires watering.
Step 4: Pure Joy
Once you have your plants in the containers, you can hang them on the wall and rearrange as needed. This is really convenient if you find out some plant dislikes too much sun or too much shade. Also it will be very easy to remove faded flowers and replace them with new ones, so that you can maintain almost a continuous display of beautiful blooming flowers.