RockScroll - A Free Addin for Visual Studio 2005/2008
RockScroll extends the scrollbar in Visual Studio 2005/2008 to show a syntax highlighted thumbnail view of your source, useful for quickly navigating long source code files.
It's just one DLL, comes with an installer and can be disabled from Tools|AddIns just by un-checking the checkbox.
Note: Does not work with regions.
Reference:
http://cplus.about.com/gi/dynamic/offsite.htm?zi=1/XJ/Ya&sdn=cplus&zu=http%3A%2F%2Fwww.hanselman.com%2Fblog%2FIntroducingRockScroll.aspx