28. A method, in a content delivery system operative in a computer network for delivering content to client machines, the computer network comprising a plurality of origin servers, each of said origin servers having resources associated therewith, and the content delivery system comprising at least one shared repeater server operable to replicate resources associated with the plurality of origin servers, the method comprising: associating the at least one repeater server with a first alias name, wherein requests for a first resource located on a first origin server are directed, based at least in part on said first alias name, to the at least one repeater server for delivery of the first resource from said at least one repeater server; associating the at least one repeater server with a second alias name, wherein requests for a second resource located on a second origin server are directed, based at least in part on said second alias name, to the at least one repeater server for delivery of the second resource from said at least one repeater server, wherein the second origin server is distinct from the first origin server; providing a table listing origin servers having content located thereon, wherein said content is authorized for delivery to client machines via the at least one shared repeater server, and wherein the origin servers comprise the first origin server and the second origin server; and wherein the at least one repeater server is further constructed and adapted to analyze, using the table, an alias name received with a client request for a particular resource to determine an origin server associated with the particular resource.
29. The method of claim 28 , further comprising: in response to a request for the first resource issued by a particular client machine, identifying the at least one shared repeater server from a set of shared repeater servers based at least in part on a network cost of delivering resources to the particular client machine; and associating the first resource with the first alias name.