It's called 'countersteering'
And yes, it is how you steer a motorcycle. As Ashton said, you don't learn kinetics intellectually, but this one can be proved. Just get up to about 25 mph on a motorcycle, take one hand off the handlebars, and push the other side with an open palm. (I'm assuming you can catch it before everything falls over.) You will definitely lean in the direction of the bar you just pushed.
Found a good link [link|http://ist-socrates.berkeley.edu/~fajans/Teaching/bicycles.html|here]. He says that the gyroscopic effect is negligible, although he is talking about a bicycle. Motorcycle wheels are quite a bit heavier.
And another link [link|http://www.survivalskills.clara.net/riding_skills_5.htm|here] focussing on motorcycles from an instructor who got tired of answering the question over and over.
I've also done the experiment with a bicycle tire. At the Science Museum in Cleveland and the Franklin Institure in Philly, they have an example of this. There's a rotating stool, like a bar stool, mounted to the floor. Nearby are several different-sized bike wheels with handles mounted on the axle, and a rotating drum you can use to get it spinning. The idea is to sit on the stool holding the spinning wheel upright, then turn it on its side. You start spinning surprisingly quickly. I can't imagine the force of a motocycle wheel/tire at any significant speed not making a difference.
