In a bid to be more "green", I use it quite often. You get to reduce wastage of disposable cups, and if you order Starbucks drinks in it, you get to save some moolah too. So, why not? :)
Of course, drinks look oh-so-chic whenever I use this pretty little thing.
It reminds me of those happy summer days I spent relaxing at the Starbucks outlet near 京阪三条駅.
Every Japanese summer, the restaurants and cafes along the Kyoto Kamogawa (Kamo River) would build の呂床 (noryo-yuka, summer waterfront platforms) from May 1 to Sep 30.
It is a brilliant way to keep off the summer heat and enjoy delicious Kyoto cuisine (and other international dishes) in the cool river breeze. Getting a spot to eat at the nearly 100 restaurants with the noryo-yuka is not easy (advance booking is recommended), nor is it cheap but if you happen to be in Kyoto over the summer months, you got to try it out at least once!
If you do not want to spend too much money, but still like to experience some time on a noryu-yuka, you can try to grab at seat at the Starbucks there. Again, it is always packed from the time it opens from about 3.30pm. It is so nice just to sit there and sip on your gourmet coffee, while people-watching....