As a matter of fact, I was doing this a lot last summer. i own a small stretch of a very small tributary to the Scottish Dee, but it is impossible to fly fish on it, due to it being surrounded by trees. i tried it out one day, with a small Hare's Ear Nymph, suspended beneath a thingamabobber, with a couple of lead weights so i could cast it out a few yards, I had much success, catching many, very small, brown trout, worked a treat for me! Picture is of a small one I caught using the above method.