Using ImageMagick instead of PhotoShop for resizing

I've gotten tired of waiting for PhotoShop Elements to load (what in the world are they doing with all that time? On my 2.3GHz box it takes 50 seconds to load). I downloaded the free ImageMagick (download it here) instead to do batch resizing on the command line. I can now convert all my images faster than it takes PhotoShop to appear. The command to resize a set of images to be 500 pixels wide and retain proportion and whose names starts with '2006-12-25-DSCN' is:

mogrify  -resize 500 2006-12-25-DSCN*.JPG