The Northern Lights do sometimes sneak a bit further south, bouncing around along the top of the Ochil Hills in central Scotland. Despite the light pollution they can be seen with the naked eye at times. I've managed to photograph them a few times over the past couple of years. Still want to go to Iceland and do it properly though.
The International Space Station. Orbits the Earth every 90 minutes (or thereabouts). When it's dark and the sun's in the right place it lights up brightly as it passes over, creating some nice light trails if you catch it on camera.