I've always loved drinking out of naturally formed substances. I like the look and feel of bamboo. In addition, bamboo is tough and durable.
There are a ton of places you can buy bamboo cups online, but those are dime a dozen. I'll outline how to craft your own, custom bamboo cup. It is unique, and it will make you feel like you are living in feudal China or Japan. Caution: you may find yourself inexplicably craving rice wine while using this cup.