Clone OSM Server

Is there any way the OSM server can be cloned, or partially cloned for use in an application that does not have access to the internet?

I think you can use Osmosis for that, especially the write_apidb task.

Osmosis can read a planet dump and import it into a mysql or postgres database. Then you can use Mapnik to render the data like you see on the OSM frontpage.

See the Rails page on the wiki.