To-go coffee is typically served full, to the brim, which leaves milk and cream lovers no choice but to dump a few ounces in the trash. If you consider that it takes about 40 gallons of water to produce each cup of coffee, you understand that the practice results in thousands of gallons of water waste with each instance. Enter a new, deceivingly simple solution: a coffee cup with hash marks along the side that make it easy for customers to indicate exactly how much room they need for milk. The concept cup is in beta at Crossroads Café in San Francisco. If implemented widely, the creators say, the idea could reduce the environmental impact of the coffee industry overall. (Consulting and materials sourcing: Excellent Packaging & Supply,; Concept: Sector Labs,