h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Another German favourite for summer is ice chocolate. Make chocolate milk/cocoa, let it cool, and serve in a tall glass with ice cream and a straw.

Personally, since the commercial powders are to sweet for my taste, I make my own concentrate in the summer. Put two tablespoons cocoa and sugar to taste (one spoon for me- the ice cream makes the whole thing sweeter later) in a jar and add just enough boiling (important - otherwise the cocoa doesn't get suspended right) water or milk to mix it into a thickish syrup. Keep the jar in the refrigerator, it will keep for a few days. To serve, put some of the syrup into a glass, add cold milk and swirl around - makes nice effects on the glass as well! The syrup also works great as ice-cream topping.