Neat Trick - Enhancing Skies

OK. Here's a neat trick that I read about in one of my Photoshop books. If you have a washed out sky, you can darken or intensify the sky pretty easily. I did notice that it intensified some of the noise of my original picture, but the effect was minimal and my camera typically has some noise with sky pictures.

• Add a layer above your picture and fill it with 50% gray
  
• Choose a Blend Mode of Color Burn. (To get to Blend Mode right click on your 50% gray layer and choose Blending Options. Blend Mode is one of the top pull down menus.
  
• So that the rest of your picture isn't darkened too much, make an Adjustment Layer (the "square with a circle in it" icon at the bottom of your Layers Palette) and using a soft black brush, fill in the areas of your photograph that aren't the sky.
  
• Adjust the opacity of the 50% Gray Layer as necessary.
  

Here are a couple screen prints of the process, followed by a before and after shot of a enhanced sky on a photo.

This was the original.

This was the enhanced version.

This was the enhanced version with Noiseware Community Edition run on it.