Smashing Magazine, the site for web designers, has an excelent collection of HDR photos. They explain;
Applied carefully, High Dynamic Range-technique (HDR) can create incredibly beautiful pictures which blur our sense of the difference between reality and illusion. In graphics HDR imaging is a set of techniques that allow a far greater dynamic range of exposures than normal digital imaging techniques. The intention is to accurately represent the wide range of intensity levels found in real scenes, ranging from direct sunlight to the deepest shadows. This is usually achieved by modifying photos with image processing software for tone-mapping. And the results can be really incredible; in fact, many artists and designers come up with some pretty fancy results.
Here are a few to wet your appetite, click on the images for photographer information;