A few short weeks ago, we beat this into the ground: http://www.roadfood.com/Forums/topic.asp?TOPIC_ID=7905&SearchTerms=sweet,tea
But if we must, we shall have another go at it.
Your info says you are from Atlanta, GA. One must assume, therefore, that either all your questions are rhetorical or you have moved there within the last week. Otherwise, you would understand.
You see, iced tea in general and sweet tea in particular are understood only within the borders of the old Confederacy and certain parts of the adjacent border states (Maryland, Kentucky, maybe Missouri). It's because of the climate; the steamy liquid air and soul-draining heat of southern summer which sweet iced tea makes endurable. If sweet tea did not exist, New Orleans would be uninhabitable in July; it would not be possible to mow one's lawn in Florida anytime between April and October (when the grass grows 1-2 inches per day) and the market for patio furniture south of the Mason Dixon would dry up and go away because no one would want to go outside, ever, from May until October. You cannot understand sweet tea if your shoes don't turn green when not worn for a few weeks; if you cannot smell jasmine, gardenia or magnolia blossoms when you open the window of a summer evening or if you do not shop at Piggly Wiggly or Winn-Dixie. Sweet tea, along with white bread, is the essential accompaniment to pork BBQ. It is a requirement to the enjoyment of summer evenings out on the lawn or veranda, watching the fireflies and the mist creeping up from the bayou or swamp. In short, sweet tea is the southern liquor of life and no where else do they comprehend it.
In other places sweet tea doesn't exist and they serve cold tea with so little ice it quickly melts. They serve it in glasses that hold so little I generally drain them in one gulp. In CA, they try to serve iced tea when they have no lemon or lime to accompany it. They serve tea with various fru-fru flavors and colorations. They just don't know what they are doing. D_mn them all!
And, oh yeah, one more thing: Next time you tell some poor waitress there in Atlanta that you'll sweeten your own tea, you might consider whistling this as you do it: http://www.stephen-foster-songs.de/MidiDat/amsong32.mid
That way, we won't have to explain it AGAIN