Magic sand looks like ordinary sand but is hydrophobic, meaning water doesn't stick to it. It forms column-like shapes to minimize its contact with water. Pour the water out, and you have completely dry sand!
This also means it is incredibly fun to play with! I did a search on Google after seeing this video, and found that making magic sand is fairly easy. Put some sand in a baking pan and bake it for an hour to remove the moisture. Then spray Scotch Guard on it, let it dry, shake it around, and repeat that process twice. When you're done, you now have magic sand!