My best guess is that this is a mature male Little Blue Dragonlet dragonfly (Erythrodiplax minuscula), resting on a branch in the heat of the summer at Buescher State Park near Smithville. A common species, the little blue dragonlet is small (less than an inch), and primarily found in the southeastern United States.
Find more photos from my 2010 Picture a Day set at: www.flickr.com/photos/matthigh/sets/72157620610035860/
You can also view my 2009 Picture A Day set that started it all at: www.flickr.com/photos/matthigh/sets/72157625855768121/
