This is pretty genius. Cuppow is a reusable plastic lid that turns a Mason canning jar into a travel mug. Um, why was this not thought of sooner?! Just this afternoon I spilled my drink down the front of my shirt while drinking out of the wide-mouth of a Mason jar (also, there may have been some general clumsiness involved). Since Mason jars are everywhere lately, and so practical for carrying and storing liquids, this just makes perfect sense. I'll take two, please!