Zero Gravity Roller Coaster
BRC Imagination Arts (from California) created a concept called Vomit Comet. That is an attraction to provide an opportunity for the zero gravity experience. According to the designing company an amusement park will have to spend $40-60 million to install such a comet, however it would get repaid pretty soon, as an attraction is to be of great popularity among visitors dreaming to experience the state weightlessness.
Via: thefabweb.com