example.rb

require "rubygems"
require "mounter"

module FooApp
  extend Mounter

  controllers do 
    get "/foo" do 
      "Foo..."
    end
    
    get "/bar" do 
      "Bar..."
    end
  end
end

FooApp.mount!
Mounter::Application.run!

mounter.rb

require "sinatra"

module Mounter
  class Application < Sinatra::Application
    def self.mount(mod)
      mod.defined_controllers.each do |name, blocks|
        blocks.each {|block| instance_eval(&block) }
      end
    end
  end
  
  def mount!
    Application.mount(self)
  end
  
  def controllers(prefix=nil, opts={}, &block)
    routes = defined_controllers[prefix||false] ||= []
    routes << block
  end

  def defined_controllers
    @_routes ||= {}
  end
end