There are a couple of ways to remove water marks from wood. White toothpaste seems to have the best results. Simply rub it on with a cloth for a few minutes until you see results. See the full instructions and other methods here.
Mosquito/Fly trap- Cut the top off a 2 liter bottle. Invert the cone and place it inside the bottle. Glue the two pieces together. Add 1 tsp yeast and cup sugar to some luke warm water, and pour the mixture into the bottle