I found this refreshing drink over on Desert Candy. It's quick, easy, delicious and just a tiny bit exotic. My minor modification of her recipe:
fresh juice of 8 lemons1 cup simple syrup (50/50 water and sugar, heated until sugar is dissolved)6 cups water1/3 cup fresh mint
Juice the lemons, fish out the seeds, add the mint. Run through a blender, sweeten with simple syrup (tasting along the way, to ensure you won't oversweeten), then do the same with the water. Serve over ice. Everyone will *love* it.