Interesting thread...
I do fairly regular aviation trip writeups, and each camera image is cropped as required and then I usually generate two images: one at 8" wide 72dpi and the other at 8" wide 144dpi.
I often wish I had an automatic means of generating those two images. I am sure Photoshop can do that using its automation facility... I have used that a long time ago to convert thousands of 100MB TIFFs (from a Nikon slide scanner) into 5MB Jpegs.