Anyone who plays sports or exercises knows the importance of sweatbands. They prevent sweat from dripping into your eyes: improving your vision, and hopefully your game. Wrist sweat bands keep your hands dry—especially important when running, or playing tennis or other racquet sports. The majority are absorbent, odor resistant, and even fashionable. They come in a variety of colors and materials, including a sweat band that is actually made from high-tech crystals that turn into a cooling gel when placed in water.