This is really simple but has a great, unusual taste. I've been on the lookout for purple basil so I could make it, and Grow Memphis's booth had it on Wednesday at the Botanic Gardens market.
Rinse basil and set it in a small pitcher. Squeeze 3 lemons and one orange, add it to the basil, and muddle it all up for a little bit. Whisk 1/8 cup agave nectar with water. Add agave, ice, and 2 cups water. Stir and pour.