>
>First of all, thanks for your help!
>
>Problem with trying your interface approach is that it appears that (looking at your example) I still have to inherit my _Default page when declaring the interface (same problem).

Try this:

If you don't have an App_Code folder already, right-click on the project and select Add ASP.NET Folder, then App_Code. Right-click on App_Code and create a new class. Let's call it Interfaces. Modify the class to include a namespace and turn it into an interface definition, ex:

namespace MyApp.Interfaces
{
    public interface IMyWebPage
    {
        void UpdateText(string newText);
    }
}

Namespace MyApp.Interfaces
   Public Interface IMyWebPage
      Sub UpdateText(ByVal newText As String)
   End Interface
End Namespace

Now go back to your user control - you should be able to type: MyApp.Interfaces and see Intellisense pop-up for the IMyWebPage interface.