For me, casting in front of strangers is only slightly easier then taking a crap in front of an audience.  That is a bit of an exaggeration but pretty close to the truth.  So, I usually don't put myself in a position where I enter a stream anywhere near where someone else is already fishing.  Still, I think about these things and have always walked downstream and started fishing below the stranger.  I assumed that meant I would not take any "fresh"water from him/her and would start in on water that they had already covered. 

This morning I was watching a show that talked about doing the exact opposite.  They said that a person coming to water that is already being fished should go to the upstream end of the lineup and fish down from there.  Now these guys were spey casting for steelhead in British Columbia so maybe they do things differently (I mean steelheading may be different, not Canadians).  They are casting long lines out into the current and letting them sweep down and into shore.  I guess that maybe they work their way down river instead of up. 

So, am I okay?  Is it cool with you that I walk downstream and fish up?  Is it just the steelheaders who want newcomers to start upriver?