using 还是 by using?

using和by using的区别，老外觉得只是稍有侧重点不同，语法上都是正确的：
http://www.grammarly.com/answers/questions/4579-usingby-using/
http://forum.thefreedictionary.com/postst26393_should-use--using--or--by-using-.aspx
http://www.englishforums.com/English/GrammarUsingVersusUsing/gzgvb/post.htm