I started using a reusable cup just in time: This Friday, Starbucks is offering free beverages to people who bring in their own cups. Of course, this doesn’t absolve them of all responsibility for the trash they generate the rest of the year. But though I don’t see people using reusable cups in Starbucks very often, the cashiers in the three I’ve been to have been very complimentary of mine. (Even if their inability to write on the side meant they mixed up my order a couple times…)