I am binding a ToolBar to a collection of command view model objects.  The objects in the collection have a property IsSeparator that when true I would like represented with a <Separator/> in the ToolBar.
My basic markup looks like this:
<ToolBar Grid.Row="1" ItemsSource="{Binding Path=ToolBarCommands}">
    <ToolBar.ItemTemplate>
        <DataTemplate>
            <Button ToolTip="{Binding Path=ToolTip}" Command="{Binding Path=Command}">
                <Button.Content>
                    <Image Width="16" Height="16"  Source="{Binding Path=IconStream}"/>
                </Button.Content>
            </Button>                    
        </DataTemplate>
    </ToolBar.ItemTemplate>
</ToolBar>
I've played around with ItemContainerStyle much like this example for MenuItems but to no avail.
Any help is appreciated.