That being said, I think it's kind of becoming a dying art to orient yourself by compass and cardinal points. Most people have a hard time thinking in cardinal points and don't seem too interested in fixing this. But that is a shame since directions such as "go right" are too relative to your reference point to eliminate confusion.
http://silva.se/product/compasses/compasses-outdoor/compass-...
Satellite dishes can be a very useful directional reference in many urban environments. Here in the UK the overwhelming majority of dishes are aimed at the Astra constellation, so they indicate an azimuth of rougly 155°.
https://apps.getpebble.com/en_US/application/540f7cafbc27450...
Because anybody would care how one proceeds? If it's meant to not seem tourist to pickpockets and the like, those can tell anyway...
I wore it on my keychain - and I still do! Doesn't come in handy as much since I know where I'm going but it's nice to carry around.
(It didn't help that cars were on the opposite side of the road too, so my baked-in "look left when you approach a road" response was suddenly not so helpful.)
My understanding is that it tells you how parallel you are to the magnetic field lines.
I don't see how that helps you find the stairs. All I can see is that if you lay it down on some steps, it will tell you whether it's pointing uphill or downhill.
Is that not correct? Do the magnetic field lines in a tube station somehow point towards the exit rather than the north pole?