Some bartenders at Moog Wine+Food (now sadly departed) in Sydney were doing foamed drinks in 2004. They did a rather good one called the Bittersweet - Campari shaken with pink grapefruit juice served up, topped with a Grand Marnier foam. Not sure what else was in it, but it came out of a pressurised whipped cream gun a la Adria. They had a few other foamy things plus some drinks which played with contrasting temperatures and what they called "dosages" (as in methode Champenoise). It worked in the context, too, as the wine list was wilfully esoteric for Sydney (Argentinian malbecs, Austrian pinots, Oregon pinot gris etc) and the food also featured dishes involving foam and Pacojet action. There was a beautifully creamy ganache made with nothing more than couverture and water. In non foam-related news they did a really neat twist on the regular dirty martini using caperberries and their brine.