Ordinary coasters just add one more piece of kitchenware that needs to be carried around and cleaned. What you need is the Silicone Grip Coaster Set from Swissmar. These coasters attach themselves to glasses, cans, cups, bottles and anything else that holds drinks you can carry around. It doubles as a drink marker, is FDA approved and BPA-safe, and can be cleaned in the dishwasher or just wiped with a wet cloth. This set includes six coasters.