Version: Photoshop 7+, Photoshop Elements 2+, GIMP 2.2.6+
A set of brushes made up of various types of clouds. Set it to a lower opacity and use one of the wispier clouds and you've got yourself some great brushes for mist, as well!
***Check out my HIGH RESOLUTION Clouds brushes here: [link]
You can download the image files themselves on my website here: [link]