The monitor you are using with your computer may be affected by which hemisphere of the earth you are in. The Northern and Southern hemispheres of the earth have different magnetic fields, each pulling toward its respective pole. Monitors with cathode ray tubes, which are the majority of desktop monitors in use today, are manufactured specifically for which hemisphere they are going to be used in. CRT monitors work by moving electron beams back and forth behind the screen, and the earth's magnetic fields act on the electron beams, pulling them toward the field. A monitor calibrated for the Northern hemisphere can still be used in the Southern hemisphere, but the colors and the image would be slightly skewed. Most major monitor manufacturers give users the controls to manually adjust the image.
LCD monitors are not affected by this phenomenon.