There's a new system/simulation in the latest release of Universe Sandbox:
Retrograde Orbit - 2008 KV42It shows the orbit of a recently discovered comet that is orbiting backwards (kind of) around the Sun.
More info from space.com:
http://www.space.com/scienceastronomy/080904-comet-origins.htmlJust run your installed copy to update or download now:
http://universesandbox.com/download/In this image we're hovering just slightly above the plane of the solar system at a distance of 83 AU from the Sun.