The computer is an ubiquitous element of modern society, nonetheless, human computer interaction is still rather inflexible. Particularly in local collaborative environments, like office meetings, the property that the mouse and keyboard exhibit of being a gateway for the individual to act upon a workspace, makes local computer mediated collaboration uncomfortable, as users have to time-share their actions upon that workspace. We present in this paper a novel, very fast, vision based interface that allows multiple users to interact simultaneously with a single computer by performing hand gestures, which are filmed by a static video camera. This interface attempts to continuously recognize predefined postures and movements using a view-dependent method. We also present A.C.O, an application which receives input from the vision based interface and allows users around a table to collaborate playing synthesized music instruments by moving their hands.