Kathleen McGrath over at the The Visual Basic Team blog has released a short (approx. 6 minutes) screencast on the Microsoft Interop Forms Toolkit 1.0, showing how to create a Windows form in Visual Basic 2005 that you can call from your Visual Basic 6 applications.
The idea is that it enables you to incrementally enhance your VB6 applications utilising functionality in the .NET framework. Might be a good solution for someone supporting an existing VB6 application.