At a recent bridal shower, we decided to freeze 100% tea into ice cube trays to add to our large tea dispenser to keep it cold and yet not to dilute it. I also froze some of my garden's spearmint leaves in a separate ice cube tray, in case anyone wanted to add it to their individual glasses!
Now that I think of it; raspberries, blueberries or even watermelon cubes could also be frozen as additions, just for fun!
(The photo is just to show you the cubes, taken after the party.)
This page contains the following solutions.
If you run out of iced tea, you don't have to make a whole pitcher. Here's how to do it for one glass.