ToolTip with List items

   
     

<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="WPF" Height="150" Width="300">
    <StackPanel Name="stackPanel1">
        <Button Content="Button with a Richer ToolTip" Height="23" 
                Margin="10" Name="button2" Width="175">
            <Button.ToolTip>
                <StackPanel Name="stackPanel2" Width="200">
                    <Label Name="label1" HorizontalAlignment="Left">
                        List of Things:
                    </Label>
                    <ListBox Name="listBox1" Margin="10" >
                        <ListBoxItem>Thing 1</ListBoxItem>
                        <ListBoxItem>Thing 2</ListBoxItem>
                        <ListBoxItem>Thing 3</ListBoxItem>
                    </ListBox>
                </StackPanel>
            </Button.ToolTip>
        </Button>

    </StackPanel>
</Window>