If Erdős is published as Erdös in a paper, which do I cite?

A proposed compromise

We cite papers to show our respect to the authors and to help our readers find stuff. For the second purpose, I suspect most people would just type in names without diacritical marks, and most search facilities would find what you're looking for based on the letters alone, so it doesn't really matter. But for the first purpose, I think you should spell the name the way its owner would want it spelled, regardless of what some journal may have done.

In response to Gil's compromise (because you can't put images in comments apparently), you can get the desired effect with \textdotacute from the tipa package from CTAN.

;-)