This post from "the paupered chef" caught my eye. It looks counter intuitive, but then I am a fan of the gibson and pickle vinegar from the onions must sneak in somehow. So I thought I'd take a taste test. I started out with the idea of a Martini, because its familiar ground and I know the gibson works. Looking through the cupboards I spotted some Sushi vinegar. This is basically rice wine vinegar to which some sugar has been added. That suggested a sake-tini or similar.
So here we go
1 barspoon sushi vinegar
1 pt Sake
5 pts Gin
Stir or shake depending on your preference.
The sake, is sweeter than vermouth, so you may have to play with the proportions to get a drink that you like. The vinegar definitely adds a certain something, but you'll probably be quite hard pressed to say exactly what. In fact my test audience were shocked to find out that the drinks contained vinegar.
I've got a couple of other ideas lined up for this as well as something more along the lines of the cocktail in the article.