The STLport organization offers an alternative implementation of the Standard Template Library. You can install the alternative instead of using the existing STL implementation shipped with your compiler. The creators of this implementation claim that it's fully compatible with VC++ 5.0 and 6.0, as well as many other platforms. You can download the STLport implementation from http://www.stlport.org/index.shtml
The site contains installation directions and extensive documentation about the STLport version of STL.