David Farkas has an interesting pair of articles on the Red Dot Forum website.
He's actually trying to get some statistical information on the question of whether people can tell the difference in real photos.
There are different ways it could have been done, but at least it's an interesting experiment - if you can spare the time why don't you vote on this - the more people vote the better the statistics.
CCD vs CMOS - part 1
CCD vs CMOS - part 2