Recent mobile devices are capable of creating and storing a large amount of multimedia data, but sharing those data with others is still challenging. This paper presents Cocktail, a new gesture-based mobile interaction system that exploits bartenders' motions. Like a bartender who pours drinks to a glass, a user can pour (transfer) multimedia data to other device. The user can also mix music files and pictures into a music video by shaking the mobile device, as a bartender does to make a cocktail. We have implemented a prototype of Cocktail system with Ultra Mobil Personal Computers and a touch-screen monitor and demonstrate its usability. Categories and Subject Descriptors H.5.2 [Information Interfaces and Presentation]: User Interfaces--input devices and strategies, interaction styles General Terms Design Keywords Mobile interaction, gesture interface