15. A content similarity-based social network establishment method, comprising: providing a content analysis means configured as device-executable code stored at a non-transitory data storage medium; providing to two or more validly-registered entities a social networking graphical user interface (GUI) as device-executable code stored at a non-transitory data storage medium and configured, when executed by data processing circuitry, to cause a display device operably coupled with a viewer's network-coupled device to display a shared window including a first content display portion, a second content display portion, and a linked-user portion, wherein: the first content display portion is operably coupled with the content analysis means; the first content display portion is configured to display content to a viewer concurrently with and in the same manner as does the second content display portion, and the linked-user portion is configured to display an identification of each linked-user and a miniature image of content with which each linked-user is engaged; detecting an engagement with first viewer-perceivable content at a network-coupled device by a first validly-registered entity of the two or more validly-registered entities; analyzing the first viewer-perceivable content by the content analysis means; identifying one or more characteristics of the first viewer-perceivable content; analyzing, by the content analysis means, second viewer-perceivable content concurrently engaged in at a remote network-coupled device of a remote second validly-registered entity of the two or more validly-registered entities; identifying one or more characteristics of the second viewer-perceivable content which are either the same as or similar to the one or more characteristics of the first viewer-perceivable content; linking the first validly-registered entity into a live, interactive social networking construct with the second validly-registered entity; and rendering the first viewer-perceivable content concurrently perceivable at the first content display portion of the social networking GUI of the network-coupled device and at one of the second content display portion and the linked-user portion of the social networking GUI of the remote network-coupled device.
15. A content similarity-based social network establishment method, comprising: providing a content analysis means configured as device-executable code stored at a non-transitory data storage medium; providing to two or more validly-registered entities a social networking graphical user interface (GUI) as device-executable code stored at a non-transitory data storage medium and configured, when executed by data processing circuitry, to cause a display device operably coupled with a viewer's network-coupled device to display a shared window including a first content display portion, a second content display portion, and a linked-user portion, wherein: the first content display portion is operably coupled with the content analysis means; the first content display portion is configured to display content to a viewer concurrently with and in the same manner as does the second content display portion, and the linked-user portion is configured to display an identification of each linked-user and a miniature image of content with which each linked-user is engaged; detecting an engagement with first viewer-perceivable content at a network-coupled device by a first validly-registered entity of the two or more validly-registered entities; analyzing the first viewer-perceivable content by the content analysis means; identifying one or more characteristics of the first viewer-perceivable content; analyzing, by the content analysis means, second viewer-perceivable content concurrently engaged in at a remote network-coupled device of a remote second validly-registered entity of the two or more validly-registered entities; identifying one or more characteristics of the second viewer-perceivable content which are either the same as or similar to the one or more characteristics of the first viewer-perceivable content; linking the first validly-registered entity into a live, interactive social networking construct with the second validly-registered entity; and rendering the first viewer-perceivable content concurrently perceivable at the first content display portion of the social networking GUI of the network-coupled device and at one of the second content display portion and the linked-user portion of the social networking GUI of the remote network-coupled device. 23. The method of claim 15 , wherein the first validly-registered entity can, either prior to the establishment of or at any time during a live social network, selectively either include or exclude one or more other validly-registered remote entities from either or both of participating in the social network and from perceiving content shared by the first validly-registered entity with the second validly-registered entity within the social network.