A cocktail aficionado is making me dinner on Sunday--I'd like to take him a cocktail-themed host gift, but it will need to be something relatively unusual, since he will have all the common liqueurs, etc. (It will also need to be purchasable at Binny's or similar.) His taste runs to gin drinks, but I'm not enough of a cocktail master to know what would be a delicious addition to his bar or a delicious cocktail to add to his repertoire. Suggestions? Thank you!