The Grumpy Editor's Guide to Image Viewers

The Grumpy Editor's Guide to Image Viewers

Then there's flphoto. It has a bunch of camera and "album" stuff I don't use, but it starts up quick, and does simple crop/rotate tricks. I use it to select a bunch of images and rotate them all 90 degrees one way or the other, and then save them without degrading the jpegs, all with many fewer than 2N clicks. It's not packaged for Debian yet.