In spring through fall, we always have a couple of pitchers (one decaf and one caffeinated) of "iced tea" in the fridge (though it's not necessarily the tea plant, if you care about that term... personally I think people are a bit snobby about having only one plant be The Acceptable Drink Herb). It's easy enough... just get a pitcher, add some tea bags to it (or loose tea in some sort of reusable loose-tea-holder or something, but honestly I'm too lazy for that) and some sweetener if that's your bag (we've been using stevia + erythritol sweetener stuff, sold as Truvia or whatever) and fill it with water, stirring once.

Now put it in the fridge.

You're done! You now have a delicious cold beverage that you can drink whenever and which costs about as little as a flavored beverage can.

"Tea" I like to drink:

• Celestial Seasonings makes a lot of "fruity" herbal tea things that are pretty good in combination with black tea. I put in half black tea bags and half peach/raspberry/mint/whatever.
• Chai, caffeinated or decaf. If you make this with Stevia or whatever, then pour it into a glass with a tablespoon of creamer, that's 1/5 or less the calories of the "iced chai" sold at a common coffee shop.
• Some combination of: cucumber slices, lime wedges, lemon wedges, mint leaves.

Takes up some space in the fridge, but IMO it's worth it. And hey, better than filling it up with soda probably...