US Patent 7537129 Lid for a disposable beverage container

A lid (30) for a disposable beverage container (32). The lid (30) includes at least a region having thermochromic properties which is/are adapted to change color upon reaching a predetermined non-ambient temperature in response to heat transfer from or to contents (40) of the container (32). Also disclosed is a lid (60) including at least one recess (62) having an internal side wall or walls (64) that substantially correspond in size and shape to the external side wall(s) (66) of a container (68). The lid internal side walls (64) are adapted to securely frictionally engage, over substantially their entire surface area, the external side wall(s) (66) of another like container (68).