module Test
  class Tester
    def takes_a_block
      yield "world"
    end

    def make_the_method
      m = method(:takes_a_block)
      self.class.class_eval do
        define_method "hello", m
      end
    end
  end
end

t = Test::Tester.new
t.make_the_method
t.hello {|a| puts "hello #{a}"}