I was checking out the Bridge City catalog and happened to come across their new Variable Pitch plane. Pretty interesting. I don't own, nor can I afford, any of their tools but it's neat to see something that we've all thought about actually put into production.
http://www.bridgecitytools.com/pages_static/vp-60.html
http://www.bridgecitytools.com/pages_static/vp-60.html