I just saw this great idea for a container garden by Suzanne Forsling for the Juneau Empire in her article How does your garden grow? She came up with a very clever and economical solution for gardening in a small, difficult environment by using rain gutters as planters.

She attached three "rows" of gutters to the side of her house. First, she drilled a few holes in the bottom of the gutters for drainage (although am wondering if you could just hang them at a slight angle and let the water run out the end....), then filled with halfway with Miracle Grow Garden Soil and dirt and planted the seeds, in this case, rows of lettuce, French breakfast radish, Swiss chard, beets and turnips.

Resulting in perfect garden rows, relatively safe from weeds and garden pests and rodents. A brilliant idea for urban lots where you don't have a lot of space for gardening.