Gutter gardening
 

Lifehacker - Gutter Gardens Grow Produce Without Taking Up Space - Food

I doubt that I could ever bring myself to screw gutters all over the side of my house (I don't have the right kind of siding anyway), but this is still a really neat idea I think. Like window boxes but...longer. :D

Interesting idea. In our location, the reflected heat would cook those poor salad greens.