If you are using Visual Studio for application development then most probably you may have noticed the lack of built-in refactoring support. At least for me it was so obvious, probably because I was used to the rich environment provided by IntelliJIDEA (http://www.jetbrains.com/idea/) for Java development. So finally did some search to see if there's any third party plug-in for Visual Studio on this aspect and guess what! The same guys who build IntelliJIDEA has a plug-in called ReSharper (http://www.jetbrains.com/resharper/). I had no second thoughts to use it based on my experience and it sure changed my clumsy feeling towards Visual Studio :)
Unfortunately it's not free, but if you are doing open source development they give you it for free. Anyway, the cost isn't sky-high to purchase as well.