This is easy. It only works with analog watches.
Point the hour hand towards the sun. Bi-sect the line between the hour hand pointing at the sun and the 12 o clock mark and you'll get your north south line.
Here's a diagram: ImageShack - Hosting :: compassjdv0.jpg
Point the hour hand towards the sun. Bi-sect the line between the hour hand pointing at the sun and the 12 o clock mark and you'll get your north south line.
Here's a diagram: ImageShack - Hosting :: compassjdv0.jpg