Judge Not? "The World's Favorite Scripture"

Of all the verses in the Bible, the one almost everyone can quote is Matthew 7:1, "Judge not, that ye be not judged." Does that mean we are not suppose to judge the sin of others? Would that really be an appropriate position for Christians to take, or does the scripture mean something different? Dr. James Merritt takes on this misunderstood verse which he calls "The World's Favorite Scripture".