The High Museum of Art in Atlanta is hosting a major retrospective exhibition of work by Henri Cartier-Bresson, now up through May 29, 2011. There is much to learn about Cartier-Bresson from the High's website even if you can't make it to Atlanta before the end of May.
There are reviews of this show here from ArtsCriticATL.com and here from Creative Loafing, Atlanta's weekly guide to cultural life in the Big Southern City.