redirect_controller.rb

class RedirectController < ApplicationController
  def show
    uri = URI.parse(request.url)
    uri.host = params[:host] if params[:host]
    uri.port = params[:port] || 80
    if params[:path]
      uri.path = params[:path]
    else
      uri.path = "#{uri.path}/" unless uri.path.include?(".") || uri.path.ends_with?("/")
    end
    redirect_to uri.to_s
  end
end

routes.rb

  map.connect "bundlesofhope/*glob", :controller => "redirect", :action => "show", :host => "www.edola.org", :path => "/giving/bundles_of_hope.html", :conditions => { :domain => /edola.org/ }
  map.connect "campwrightwood", :controller => "redirect", :action => "show", :path => "/campwrightwood.html", :conditions => { :domain => /ladiocese.org/ }
  map.connect "creditunion/*glob", :controller => "redirect", :action => "show", :host => "www.efcula.org", :path => "/", :conditions => { :domain => /ladiocese.org/ }
  map.connect "*glob", :controller => "redirect", :action => "show", :host => "ecs.edola.org", :conditions => { :subdomain => "odr" }
  map.connect "*glob", :controller => "redirect", :action => "show", :host => "lifeformation.diosohio.org", :conditions => { :subdomain => "anglicanacademy" }
  map.connect "*glob", :controller => "redirect", :action => "show", :host => "stpaulsmodesto.diosanjoaquin.org", :conditions => { :subdomain => "stpaulmodesto" }