We have 68 Centos server diff version 4.X 5.X, we dont want internet for update errata patches. Alternative like redhat satellite server in centos which use to update all the server local.
you could setup a local yum repository on one server and update your server with that. here is a doc which also describes how to include updates.
a more sophisticated way would be using spacewalk. it is the open source software on which red hat builds its satellite server.