[bmunro]

The article you linked to describes the angle of plane of the orbit - the circle it makes around the sun. These vary by only a small amount.

The axial tilt is different. It is basically how far the axis through the poles of a planet is tilted compared to the plane of its orbit. This is what you were thinking of initially - it can very a lot.

[wkdown]

Pluto, while no longer a planet, as an inclined orbital tilt as well. It will also occasionally come inside the orbit of Neptune.

http://en.wikipedia.org/wiki/Pluto#Orbit_and_rotation