this wasent my question dis is stupied lol ha!

Magnetoresistance is an effect observed in (ferro)magnetic conductors.

When applying an external magnetic field to the conductor, the resistance of the conductor changes.

The resistance is minimized when the magnetic field is aligned parallel to the conductor, and maximized when the magnetic field is aligned perpendicular to the conductor.

This effect was first observed by W. Thomson in 1856, and changes in resistance are usually below 1% at room temperature and higher at lower temperatures <5K

For further reading:

http://en.wikipedia.org/wiki/Magnetoresistance

http://en.wikipedia.org/wiki/Electron_scattering

mr means magnetic resistance ang gmr mean gaint magnetoresistance

for the discovery of Giant magnetoresistance (GMR)

Are you refering to Albert Fert and Peter Grünberg? They won the Nobel prize for Physics in 2007, for their discovery of giant magnetoresistance.