Nodejs异步

http://cnodejs.org/topic/4f16442ccae1f4aa2700113b

http://cnodejs.org/topic/4f16442ccae1f4aa27001123

http://www.infoq.com/cn/news/2011/09/nodejs-async-code

http://repository.jscex.info/master/samples/async/sorting-animations.html

http://cnodejs.org/topic/4f50dd9798766f5a610b808a

http://blog.csdn.net/zhangxin09/article/details/6196746