After I saw this I was quite excited by the simplicity of the way to find north. But in fact, it found the 15 minutes to wait bothersome.
So here, by the way Detective Conan used this way too, is 'my' way to find north easily without waiting 15 minutes. In fact you have to have at least a watch to find north THIS way. In the case it is an analogue watch - you are lucky time-saver. But though you know how to read an analogue watch, it will also work with a digital watch because you can somewhat imagine the needles of the analogue one.
Step 1: Supplies
I am going to make this one quick (and also the hole Instructable).
Here is what you need:
1. a watch (like written in the intro)
2. the sun (you don't have to have a good sight, you just have to barely know the position of the sun)