15. The computer-readable storage medium of claim 10 , wherein the interaction condition specifies an action a user avatar performed with a given virtual object present in the virtual environment.
16. The computer-readable storage medium of claim 15 , wherein the action performed with the given virtual object is selected from at least one of a user avatar touching the given virtual object, the user clicking on the virtual object with a mouse cursor, and a length of time the avatar of the user interacted with the virtual object.