A compass has a bar magnet inside pivoted on a small point that allows it to spin freely. The 'North' end of the magnet is attracted to the true north point at the North Pole, because the magnetism at the pole pulls the end of the magnet in that direction.
As opposites attract (in the magnetic world), the 'Northern' pointer is actually charged the same as the South Pole. Which makes one wonder ... do the two opposing polls of the Earth attract each other (seems obvious they should) and what effect does this have on the Earth? I smell a good hub in this question. :)