What is Geomagnetic Propulsion?

Geomagnetic Propulsion is a technology based on the magnetic forces between an electromagnet and the Earth's magnetic field. Now as any good physics student knows, a magnet suspended by a string will rotate until it is in alignment with the Earth's magnetic field. No matter how strong the magnet is, the best it can do is behave like a compass. But if we were able to convert the torque on the magnet into a linear force, we would have a useful propulsion system! Recent progress in this area has been very encouraging. Once we have the ability to generate a net force, the next hurdle will be to find a way to vector that force in any direction. The result will be a true field-effect propulsion system capable of generating lift without wings and attitude control without rudders and ailerons. Since a geomagnetic craft won't have an engine, flight noise will be minimum. Furthermore, since rockets are limited in speed by the velocity of their exhaust, and a geomagnetic craft doesn't expel anything, it's speed will be limited solely by wind resistance.