It is located here http://www.gunn.co.nz/astrotour/ and you should definitely go check it out.
You get to play around with different view points (center the view on Earth and you can see how the planets move in relation to us), show trails behind the planets to let you view their relative orbits and much more. It's amazing to watch and really easy to use.
The orbits of the nearest planets
It even has a tour explaining the retrograde movement of the planets (as viewed from Earth) which you can see here http://www.gunn.co.nz/astrotour/?data=tours/retrograde.xml.
Retrograde movement is (as the picture below shows) the apparent 'backwards' movement of the planets at some point during their orbit.
This is due to the fact that all the planets orbit the Sun at different speeds. As the Earth moves past the planet in its orbit around the Sun, the planet will appear to move backwards in the sky.
The link above explains this clearly.
The apparent movement of Mars (blue) and Venus (green) as seen from Earth
I don't know whether or not it is scientifically sound, but it's quite cool :-)