Here are a few pictures I took of the international space station for the first time, showing it trace a line through the sky as it follows its orbital path. I very highly recommend everyone try this themselves, it is truly amazing and something you will not soon forget. You do not need to be in an extremely dark place to see it either, on very bright passes it can be brighter than the full moon, quite hard to miss. The ISS orbits relative to the surface of Earth a 22,000 km/h, so it moves quite fast, often only having a duration of two minutes. A good rule of thumb I have found is, if you can see Jupiter and Venus, you will definitely be able to see it, even on its darkest passes.