The Effects of a Polarizing filter

In this digital age of photography, what's the point of adding a special filter to your lens when basically every kind of filter can be reproduced in Photoshop?
That was the premise I was working under on my recent trip to Arizona. So armed with my polarizing filter I took a couple test shots to show you the difference. It is true, basically every filter under the sun can be applied in post production (even Tiffen, one of the top producers of filters back in the film days... and still today, has produced a digital filter software so you can apply these effects to your images on the computer).
Except the circular polarizing filter! Technically speaking, this handy little piece of glass only allows certain rays of light into your lens (for a more scientific explanation try google). The result? When used properly it will cut reflections, give you deeper blue skies and richer color.
As you can see in the picture above (of Cathedral Rock) the sky is a deeper blue and the rock is a richer red/orange color. Now granted, some of the "without" side is shaded, but even looking at the non-shady areas, the results are as plain as day.
It is important to note here that neither picture has been edited! They were taken hand held, with the exact same camera settings, one after the other. I then merged the two together and added the text, that's it. It would simply be impossible to match the un-polarized shot with the polarized one in Photoshop, no matter how hard you try.

Stay tuned for the full Arizona set in a couple days... especially if you like pictures of rock!