This is the drink that started my love for Campari. It is dead simple: A shot of Campari floated into a tall glass of orange juice. While popular in Germany, it's unknown in the States. I resorted to ordering "a glass of OJ with a shot of Campari in it." With the vitamin C of the OJ, and the natural medicinal taste of the Campari, I'm sure it's the best thing for you when you have a cold.
In my mind, the proper pronunciation is Campari Oranzh, not orange like you're asking the guy in the Acme for the bags of Florida citrus. But I am pretentious.
To float, flip over a teaspoon so that the bowl is up and touch to the side of the glass. Slowly pour the Campari over the back of the spoon and towards the glass edge.