My first experiments with High Dynamic Range Photographs (HDR modifications) I am using HDR Darkroom software .
In the past I looked at Photomatix and read Ferrell Mc Collough's book: A Complete Guide to
High Dynamic Range Digital Photography. HDR Darkroom seems to have the controls that
I can use successfully. You will either like or dislike HDR photographs. Many exaples on other sites are
very exaggerated - over the top, I think. Many may look unnatural and too saturated.
With this program it is possible to open one RAW file to modify or (generally)
3 jpegs files exposed at +1 or+ 2, 0, and -1 or -2. The software offers many options!
Click each example to better see the results. BEFORE on the LEFT, AFTER on the RIGHT.

Many excellent articles from Outback Photo

HDR before
HDR Examples
HDR Examples
HDR Examples
With this example I tried to finish it with Paint Shop Pro
to look like the 'after' example.
Modified with HDR Darkroom. It doesn't have an
exaggerated look, but could have.
HDR Examples
HDR Examples
HDR Examples
Quite blah, isn't it?
Yes, this is exaggerated, but so much better!
Before
After
Found at Sleeping Lady Retreat Center in Leavenworth WA.
Before
After
HDR versions can certainly help photos taken on a dull day - Bridge Creek, near Leavenworth, WA
Before
After

I very much appreciate what HDR Darkroom can do, especially for photos taken in less than optimal light.
Using the program colors are brought out so nicely. Unless I shoot 1 RAW image I will need to bracket exposures including
a +1 or +2. In the past I have done 3-shot bracketing but rarely have included a + image.
+1 or +2 shots will open the
shadow areas while -1 or -2 shots will help not having the highlights blown out.

I am having much better results using 3 jpeg images rather than 1 RAW shot. RAW shots, when
brought into the program, show a great deal of noise that the program does not handle (It's on their 'to-do' list).

A page with 3 shots of different exposure settings - and the final photo.   (Use Aperture priority, not shutter priority.)

A Gallery of more of my First Attempts

What is HDR? from an HDR Tutorial

A World in HDR by Trey Ratcliff - to be published soon!

Photomatix Review

Very interesting HDR examples from many photographers.