If you're looking for a stainless steel insulated bottle that will keep your beverage cold or hot, clean easily, and cover the drinking parts so that they don't get dirty, I recommend the Zojirushi stainless mug that comes in sizes up to 20 oz. I tested mine by filling it with ice cubes and leaving it on the counter at room temperature and found that the ice melted at a rate of about 4 oz/day and boiling water was still at 160 degrees 48 hrs later. The opening is large enough to pour in a cup of ice once you're on the plane.