This is a variation on the Cocktail classic, the Sidecar. Instead of it's Brandy-based relative, this recipe uses Gin. It also goes by the name the Chelsea Hotel or, simply the Gin Sidecar. Rim a chilled cocktail glass with a lemon twist. Combine the other ingredients (gin, orange liqueur and lemon juice) in a cocktail shacker, with ice. Shake well, (or if you prefer a smoother cocktail, stir) and then strain into the glass. Garnish with the twist.