While slaving over the computer (it is begining to feel that way) I came across a few more tools I wanted to pass along for working on your images The most impressive is Luminosity Mask by Tony Kuyper.
This is just one of several tutorials Tony gives on his site. http://www.goodlight.us/writing/luminositymasks/luminositymasks-1.html
While you are there check out Tony’s work. If you are not familiar with his work it is well worth your time. If you know of Tony I am sure you will agree he is one of the finest photographer shooting in the southwest today.