Yes, yes, we should all bring our own mugs when we go to Starbucks. But failing that, wouldn't it be nice if we could eliminate plastic waste from the equation by leaving off the lid? Designer Peter Herman's Compleat cups have a clever folded design that provides cup and lid in one, giving you one less thing to throw away. When they go into production, which will happen at some as-yet-undetermined future time, the cups will hopefully be waterproofed with cellulose-based plastic, making them 100 percent compostable.
Startup Radically Reinvents The Disposable Coffee Cup, Eliminating Plastic Lids, Co.design.