I did not know this, but VS2005 ships a library of re-usable and re-distributable images.  http://msdn2.microsoft.com/en-us/library/ms246582(VS.80).aspx.

You can use them in your own applications, to make them look and feel like VS.

Normally you will find it in <program files>\Microsoft Visual Studio 8\Common7\VS2005ImageLibrary\VS2005ImageLibrary.zip