Although I have no real idea as to this drink's origin or if it really has anything to do with Italy, the Italian restaurant I worked at over the summer served this concoction under the name Italian Iced Tea. Tasty stuff, and I don't even like regular iced tea. It was one of the six cold teas we served (regular, apricot, passionfruit, blackberry sage, ginger peach, and Italian) and our house specialty tea.

Brew your iced tea as you prefer it and proceed from here:

By the glass:
one small scoop lemon sorbet
one packet NutraSweet or equal
fill glass to top and stir till frothy.
garnish with mint leaves.

By the pitcher: (tastes better as the proportions mix out better.
fill pitcher roughly 1/4 full of sorbet--loosely scooped. do not pack.
6-8 packets sweetener, to taste.
stir until the tea is somewhat opaque and frothy. Pour, garnish with mint, and serve immediately.