expando.rb

class Expando
	def method_missing(method_id, *arguments)
    if match = method_id.id2name.match(/(\w*)(\s*)(=)(\s*)(\.*)/)
       puts match[1].to_sym 
       self.class.class_eval{ attr_accessor match[1].to_sym } 
       instance_variable_set("#{match[1]}", match[5])
    else
      super.method_missing(method_id, *arguments)
    end  
  end    
end

person = Expando.new 
person.name = "Michael"
person.surname = "Erasmus"
person.age = 29