Some great discussion by people who really know how to use Google Earth is here:
http://bbs.keyhole.com/ubb/showflat.php/Cat/0/Number/992512/page/0/fpart/1/vc/1

Some have even found whole airplanes, probably in flight!

I worked 30 different coordinates then panned and zoomed and scrolled around the points looking for stuff. Reported about 17 different anomalies but I don't think the resolution is there. And the wreckage is probably crumpled so is even less likely to be detectable with that image resolution. Just for scale consider that the wingspan is about the width of a 2 lane road. Now break the wings off. Would a single wing be discernable?

That they are finding old wrecks previously unknown is a sign that they are really doing a great job combing the territory.