In São Paulo, Brazil, there's an office building called Harmonia 57 that has a façade covered by plants. They got there because of pores built into the concrete, where foliage can be planted and grow out until it covers the outside of a building. Since it's all part of the design, the architects at Triptyque also included a way to get the plants plenty of water, by way of a misting system that sprays the façade.
It sure does look pretty, though we've seen some greener setups. Still, that mist would be nice to walk under in the summer, I bet. Triptyque is using Harmonia 57 as a prototype for it's plant-covered-building concept.