Take a 2-quart pitcher and put 1 cup of sugar (or 1/2 cup sugar and 1/2 cup granulated artificial sweetener like Splenda), 1 thinly sliced lime, 4 or 5 sprigs of mint in the bottom, and muddle. If you have a wooden spoon, use that.
Let sit while you are cooking dinner. In a pot, add 4 large black tea bags to 6 cups cold water and bring the water to a boil. When it starts boiling, turn it off and let the bags steep in the hot water. When dinner is ready, add the cool tea to the pitcher with the sugar/mint/lime mixture. If the tea is hot, it will crack your pitcher. If it is warm, put a metal spoon in the pitcher and add the tea a bit at a time. The spoon will absorb some of the heat. Fill the remaining space with ice (to make 2 quarts) and serve. Add rum if you like, as much as you like.