A while ago i was thinking that i would be nice to have a control that exposes multiple designer panels, but only shows one at a time… Somewhat like a TabControl, but without the header.. Anyway, i found out (here) that a TabControl can be tweaked into that behaviour

public class MultiPanel : TabControl
{
	protected override void WndProc(ref Message m)
	{
		if (m.Msg == 0x1328 && !DesignMode)
		{
			m.Result = (IntPtr) 1;
		}
		else
		{
			base.WndProc(ref m);
		}
	}
}

In the designer it appears as following

And at runtime it appears as following