I don't know what it is, Mary, but I do know it's not a rhododenron bush, which has rounder clumps of blossoms. We have lots of them in Atlanta. http://en.wikipedia.org/wiki/Rhododendron
It kinda reminds me of a butterfly bush, but I don't think it's that either. I wish I were a flower expert, but I'm not!
Mary MacADNski: The leaves are what remind me of the rhododendron. It's a mystery.
It's a "Pieris japonica" Common name pearl flower, Lily of the valley Bush. They are native to North America and Asia This picture is better than the one in my gardening book. I just happened to remember seeing it last time I was looking for a hardy shrub to put in a new garden bed.
Mary MacADNski: I knew someone would know what it was. Thanks so much, Aussie. I'd never seen one before and thought it was really striking