Why does aurora occur? If we simplify, auroras occur when charged particles from the Sun hit Earth's atmosphere and interact with atoms present in the atmosphere - atoms get excited in the air and colourful view is created.
Auroras haven't been observed only on our planet, but also on Jupiter, Saturn, Venus, Mars, and some of the moons Io, Europa, and Ganymede. (all Jupiter's)
Check out this time lapse, it's pretty cool and it gives you some idea of aurora's dynamics. (although in reallity it's much much slower)
Earth's auroras observed from Earth:
Earth's auroras observed from space:
Jupiter's and its moons' auroras:
Yeah, auroras are pretty damn awesome and they are worth going hundreds of kilometers north or south to observe them! Lucky those who live there...
Of course, when Sun's activity is really high, auroras are visible in other places - like in 2003, when auroras were visible throughout the Europe.
And with Sun's new maximum on its way we can hope for more continental auroras.
Space Weather - This site keeps us alert for any auroral activity as well as Sun's activity.
Space Weather's galleries - In Summary section you've got link for previous month.
POES (Satellite) - Real-time auroral activity derived from satellite.