I love double walled tea cups. Generally they don't have a handle and I love the smoothness and ability to hold the cup from any side. Some of the best known are these Bodum double walled tea cups.
The double wall helps to insulate your hand from the heat of the liquid inside. And it also gives the tea a neat appearance as it appears suspended in thin air. They are made from borosilicate-glass to withstand both hot and cold liquids.
You can get just the Bodum tea cup or they also make an infuser tea cup that has a lid and steeping basket to make a single cup of loose tea. After steeping the lid holds the steeping basket to contain any liquid when the tea leaves drain. This version comes in black, green, orange, and red. Pretty and functional too!
There is also a handled version of this tea cup too, in case you prefer one.