I was trying out various settings in the Apophysis fractal flame program and this angel popped out. I used a Hue-Saturation layer to emphasize the halo and masked a few wisps here and there, but otherwise this is untouched. The font is Trajan Pro with a drop shadow and a one pixel stroke.

'For behold, I bring you tidings of great joy...' -- I've always been fond of St. Luke's version of the Nativity.