Save money and the environment with a TapGuard ($16). Made of food-grade silicone, the water bottle filter removes up to 95% of chlorine, iodine, and other bad stuff from your tap water. It fits Camelback, Nalgene, and most reusable widemouth bottles. It's available in black, blue and orange, and comes with two replacement carbon filters. We've been using the TapGuard with the Guyot Standard stainless steel bottle ($25), which we also recommend.