We often get posters (usually woo-mongers) resorting to the Einstein quote "Imagination is more important than knowledge".
I've just finished re-reading Gleick's Genius: Richard Feynman and Modern Physics (also published as Genius: The Life and Science of Richard Feynman).
There's a very pertinent quote (on page 324 in my copy):
“The whole question of imagination in science is often misunderstood by people in other disciplines,” he said. “They overlook the fact that whatever we are allowed to imagine in science must be consistent with everything else we know… ” and "...not just some happy thoughts which we are free to make as we wish, but ideas which must be consistent with all the laws of physics we know. We can’t allow ourselves to seriously imagine things which are obviously in contradiction to the known laws of nature. And so our kind of imagination is quite a difficult game". (Emphases in the original text).
So, rather than argue the point the next time someone uses Einstein's quote as "support" for drivel just point them to this post (made a sticky).