Whenever a cork ends up down in the bottle, I have used a variation on the shoe method to fish it out:
1. remove shoelace (preferably a thick, cotton one)
2. tie a big knot about 2" from one end
3. shove knotted end of shoelace into bottle, using a chopstick, until it grabs the cork
4. gingerly at first, pull the cork up to the neck, then after it's positioned use full strength to pull it out.
This method was taught to me by my friend, sommelier and bon homme, Peter Birmingham.