I just came across the Neutron project via an email (thanks Anthony). It looks very cool. Check out the screen shots. I have to drill down and see how much code you have to write to get the shapes to work but I can think of lots of uses for this. I wrote something ages ago like this in VB6 but it was nowhere as nice as this.
Take a look at my TaskBuilder app, if you want to see how some shapes are implemented.
http://blogs.conchango.com/howardvanrooijen/archive/2005/02/07/934.aspx
Otherwise if you download the full Netron Library, there are plenty of Advanced Shape examples.
Also Netron Light is work a look as it’s far less complicated than the full Netron Library - I think it’s easier to get started with, before you upgrade to the "Daddy". Take a look at Francois CodeProject article about it.
http://www.thecodeproject.com/cs/miscctrl/NetronLight.asp
Lithium (a tree control) should be released soon - it’s pure dynamite.