Today I experienced the revelation. Firefox is my browser and FeedDemon is my feed reader. Each time I clicked on the links in FD, they would open in Firefox and the newly opened tab would take focus. Switching back and forth was a pain.
I say was, because it no longer happens, since I installed Firefox 1.5. I think there was an option in 1.0.x that promised something like that, that I tried it and it didn’t work. Whatever the reason, now it works.