A really cool and useful tool I found for Visual Studio is RockScroll.  According to Scott Hanselman, RockScroll is an internal tool that developers at Microsoft uses.  RockScroll basically has two cool features. One, it converts your visual studio’s scroll bar to show a mini version of your source code outline, very helpful when you have hundreds of lines of code on one page, and two it highlights similar words when you click on a word in the text area, which makes it very easy to follow variables within your code.  Works on both Visual Studio 2005 and 2008.