All credit to kryo.
"Having just recently transitioned to Visual Studio 2010 (finally) at my day job, I found myself in a bit of a predicament.
Previously we'd been using VS2005, for which there was a little extension called MetalScroll (based on another named RockScroll); this extension changed the scrollbar into an actual thumbnail of the code in the editor. For very large and complex files, this makes navigation considerably easier and quicker because you can learn the code's physical layout and identify important locations in the code by sight.
Unfortunately, as of VS2010 all extensions have to use WPF; MetalScroll was a Win32 extension and the author had no interest in rewriting it for the new version."
-- I'm just trying to get this to install on my machine. - DG