Creating drag handles

[David Keaveny]

Firstly - thanks for such a nice piece of code!

Secondly, how would you implement a drag handle? For instance, if I'm building something like Visual Studio's Entity Framework model designer, and I want to be able to drag a "entity" around a canvas, I might have a control something like this:

<UserControl>
    <Border Thickness="2">
        <DockPanel LastChildFill="True">
            <TextBlock DockPanel.Dock="Top" Text="{Binding TableName}" />
            <ListBox ItemsSource="{Binding Columns}" />
        </DockPanel>
    </Border>
</UserControl>

How would I make the entire control draggable only if the user was clicking on the TextBlock? If the user clicked on an item in the ListBox, I would want to initiate a completely different drag-drop operation.