"A considerate cartographer wielding a stencil and a can of spray paint has left a helpful navigational compass at the top of the stairs outside the NRW train at Prince Street for commuters exiting the station. As even native New Yorkers cant attest, everyone has exited a subway station and needed a moment to reorient themselves; a directional compass will make it that much easier. The unknown compass crusader stenciled the sidewalk at the uptown 6 train station on Spring Street as well. "
http://nyctheblog.blogspot.com/2010/06/sidewalk-graffiti-provides-navigational.html
I love simple, unobtrusive signage. It can be used in physical space and virtual space. Brainstorming on this example from NYC that painted a compare rose at the exit of subway stations you could use the same technique too
* point to bathrooms near parking
* point to information booths
* point to insert-your-favoriate-coffee-franchise-here
What would you point too?