SyncHole is a set of Winamp plugins (one General, one DSP) that allow an arbitrary number of Winamps to be synchronized over a network, producing the effect of a single, all-encompassing Winamp.
One Winamp will run the General plugin in Server mode, and all of the other Winamps will run it in Client mode. The server commands the clients to play the same physical file that it's playing, and also relays to them any Play/Stop/Rewind/etc. commands that are entered in its own local interface...