I switch often between c++ and web development in VS 2008.  There is a command line switch that allows you to switch environments. 

Here's the command line switch:

devenv.exe /ResetSettings settingsFile.vssettings

My short cut setting ends up looking like the following for C++

"D:\Program Files\Microsoft Visual Studio 9.0\Common7\IDE\devenv.exe"
  /ResetSettings "C:\Some Dir\My Documents\Visual Studio 2008\Settings\c++-2009-06-04.vssettings"

My web dev startup looks like:

"D:\Program Files\Microsoft Visual Studio 9.0\Common7\IDE\devenv.exe"
  /ResetSettings "C:\Some Dir\My Documents\Visual Studio 2008\Settings\Web-2009-06-19.vssettings"

Unfortunately, starting up VS 2008 this way takes time.  Lots of time.  I've been playing with VS 2010 beta, and it seems to have the same issue.  Why change settings?  Try opening a web project with C++ settings and you will see what I mean.  Menu options are missing.  I played around with customizing the environment, but I am not enough of a VS 2008 whiz to get it the way I want it.  Perhaps I'll dive into it some rainy Saturday now that football season is over.

Looks like the real solution would be to have VS 2008 setup on two different VMs.  My D drive is always mapped to virtual machines anyway, so everyone has access to the VSS database.  All it takes is time, a few Gigs of RAM and a TByte of disk, right?