Coke's all about sharing, as evidenced by the brand's "Sharing Can," created via Ogilvy Paris and Singapore. But why sell only one Coke when you can sell two? Leo Burnett in Colombia devised a method to get freshmen at colleges to become friends -- and sell twice the amount of soda -- with "Friendly Twist," a bottle with a new type of cap that can only be opened with another bottle of Coke.