1. A method for moderating transmission of a media source file from a media source owner computer to a receiving computer, the method comprising: wirelessly connecting at least three client devices to a host system having a shared display, wherein one of the client devices is the media source owner computer, another of the client devices is the receiving computer, and another of the client devices is a sender computer; receiving, from the media source owner computer at the host system, a visual representation of the media source file; displaying the visual representation on the shared display as a worksurface image; sending, from the host system, to each of the connected client devices, worksurface image information including position of each shared visual representation in the worksurface image; receiving, at the host system and from the sender computer, control information indicating to share the media source from the owner computer to a recipient, the control information based on interaction with the visual representation of the media source file within the worksurface image on the sender computer, the recipient being the receiving computer; verifying permission to transmit the media source file and permission to receive the media source file by: receiving permission information pertaining to the media source owner computer and to the receiving computer; examining the received permission information to determine whether the information is sufficient to authenticate permission from the media source owner computer and from the receiving computer; and if there is sufficient stored information to authenticate said permission, then transmitting, from the host system to the media source owner computer, a request to send the selected media source file from the file transfer system to the receiving computer.