What do the numbers in the Case-Shiller Index mean to us right now? Obviously, if one is in Las Vegas or Miami, it's not time to break out the champagne, but what about, say, Atlanta?   Or Charlotte, or Denver, for that matter?  Are small gains in month to month prices really making a difference in our sales, or perceptions?  I'd like to hear from someone in those markets-is it filtering down to street level, or is this index a "Wall Street" number, useful in the whole, but not too predictive locally.......