notes.txt

The idea is to be able to examine a path inside a #defer_to block and 
optionally rewrite parts of the request — path, subdomain etc. After the
rewrite, the request will go through the router again, where any matching 
routes will then pick it up.

router.rb

match("/:locale/:dialect/:full_path", :full_path => /\S+/).defer_to do |request, params|
  if is_clever? params[:full_path]
    rewrite(params, :subdomain => "admin", :path => "/bongst")
  else
    params
  end
end