http://www.naturephotographers.net/arti ... 310-1.html
It teaches how to blend exposures in Photoshop Elements, which is generally accepted as something that requires full on Photoshop. It looks like it will work best with a straight horizon (as will most blending techniques). This is a technique that replaces the use of a GND in the field. It is essential to use a tripod in the field and take two identical compositions with different shutter speeds (don't adjust the aperture... keep it on fully manual or shutter priority)... One exposing the ground correctly and one properly exposing the sky. Upload your two shots, import into Elements and follow this tutorial for some sweet results

Basically, if you have a camera with manual controls (certainly does not have to be DSLR), a tripod and a copy of photoshop elements, you can take some bad@$$ sunrise/sunset photos using this technique.