HDR with RAW files
While I mentioned HDR on a previous entry, at the time I comented the need of three (or more) different exposures to obtain an HDR image. More recently I have learned that you can use the same software to obtain the same result with just one photo.
The basic idea is that camera sensor have significantly more resolution than the 8 bits per color of JPEG. Some cameras -- unfortunately the most expensive ones -- allow you to access to the original sampled data. The so called RAW format. After some processing a JPEG file can be obtained changing, for example, the exposure one f-stop up or down (this is like dark-room magic).
In the above image I took a single exposure and I used Canon's RAW processing software to obtain three JPEG files with exposure values -1, 0 and +1 from the original shot. Then the three were combined with (the trial version of) Photomatix software.
Original shot is shown below for you to compare.
Update: Actually, thanks to one of your postings I've learned that Photomatix can also take a RAW file as input to create an HDR file. So there is no need then to create three or more different exposures from the original RAW file. Some samples in here.