About a month ago I purchased some TerraTrade Drain Pipe Planters off of Amazon.com. I got 2 sets of 3. Amazon has them for sale for 9 dollars for a set of 3 and if you spend 25 dollars you get free shipping so they are only 3 dollars a piece. I placed one Grape Hyacinth plant in each pot then hung them on our drain pipe. I did drill a hole in the bottom of each pot to drain water so the plants did not drown in a rain storm.
They are definitely small but you can still fit one small flowering plant in there with out any trouble and they really have a romantic exotic look hanging on your drain pipe! It is really nice especially if you don't have a lot of space in your yard!
The picture below is a close up look at one of the planters not attached to a gutter. I have a pineberry in it at the time that I have since transplanted to a larger pot.