Jon Galloway posts about
opening a file in explorer from within another app. He even offers a little code snippet so you can add such functionality to your own apps. Nice.
He highlights the "Open Containing Folder" functionality in Visual Studio 2005...

I use this feature
a lot but what I still don't get is why they added this to the context menu of the tabs but not to the context menu of the solution explorer?
Fortunately you can add this functionality to VS2005 by installing the excellent (and free)
Cool Commands from
Gaston Milano. It does much more than add an open containg folder to the solution explorer too -
check it out.

I initially had trouble installing CoolCommands using the msi on Vista but it worked fine when I launched it from an elevated (Run as administrator) command prompt using msiexec.