Like Scott Hargis says, there are a gazillion ways to replace a sky. For real estate photography you want something fast and easy. Scott's video tutorial is just that, quick and easy. You don't even have to have a library of skies for this one! You just change the color of the clouds from grey to blue. Great idea!
Scott also describes a nifty little trick for removing the power lines.
This technique will work for any version of Photoshop or Photoshop Elements that has the magic wand in it. It's been in PSE since version 6 and I think it's been in Photoshop longer than that. So this is a technique that anyone should be able to use.
Thanks to Scott for this tutorial!