Frozen concentrated tea cubes
I wish someone would market frozen concentrated tea cubes in a size that would be suitable for one glass of tea. You could add plain tap water and stir for an instant cold drink. I know that concentrated tea in a jug is available but it tastes more like lemonaid than tea. I think the lemon may be there to help preserve it or to camouflage an off-taste. I think it would not need the lemon if it was frozen. Of course there could be more varieties available - one with just tea, one with lemon, maybe some with fruit flavors like raspberry.
Reward: just to be able to purchase it at the local grocery store