misinformation is the one that gets to me.
you get people answering questions, in great depth, with incorrect information they got from fark knows where, and unfortunately, the person who asked the question has no idea they are being fed a load of bs. then a few more readers, with little to no idea, read the misinfo, and pass it on again at another stage.
my suggestion is, if you see this going on, BITCHSLAP THE OFFENDER, preferably in caps, and then rectify the problem by giving the correct info.
as far as search goes, i think you'll find that a high percentage of readers know the answer to your question because it has been answered so many times before. and they are all thinking the same thing. SEARCH!
in this case, i usually give a short answer, and/or a link to one of the many threads where this has been covered. as does NISMOID the search nazi . its the right thing to do