I think these vertical gardens, or green walls as they are sometimes called, are one of the best new design ideas in ages. One of the top designers is Frenchman Patrick Blanc, who has a nice web site. This is the Musee de Quai Branly in Paris.
A parking garage in Lyon.
Two images of Blanc's Madrid garden, right after it was planted, and after the plants had grown.
A highway overpass in Provence.
A private office in Belgium.
Les Halles, Avignon.
Although I like these, I have to say that I think the environmental benefits are oversold. Yes, more plants are always better, but for the cost of one of these you could plant a lot of trees.