We love the idea of a tiny garden in our balcony. Every spring we try to do something there. Put up a few plants. Some flowers and some herbs. The kids do enjoy the yearly trip to the nursery and then watering the plants to death :)
But this is really about the totally amazing tiny little 40mm prime lens that Canon makes for their DSLRs. It costs less than $200 and goes down to f/2.8. It is virtually negligible in terms of weight and size and is a great walk around lens. I'd even recommend it higher than the regular 50mm lens.
Image quality is good but not great but will serve well for most practical purposes. An added advantage is that it can do a bit of a macro with the focus distance (minimum distance from the sensor that the lens can focus) just under a feet.