“Take Control of Your Digital Photos,” Chapter 5
You need to be judgmental about your images. Why? Judging your photos achieves two goals. It sets up a practical workflow for later, so you know right away which shots you want to share with others and which ones need work in an image editor before being ready to be made public (and which should be deleted or hidden). Judging also helps you become a better photographer, because it helps you look at your shots critically to determine what you’re doing right or wrong, and in what areas you excel or need to improve. In this chapter, I offer a system for judging and flagging your photos to make them most useful in your library. I also discuss what to do with the shots that don’t make the cut.
The "reject" dilemma that I face most commonly is (sometimes from using "bracketing" multi-shots for sports or birding) that I often end up with multiple, nearly identical "OK-or-better" shots.
Your advice?
If you have a lot of shots that are basically the same, then I'd pick one or two and cull the rest. Or, you can put them into stacks (Aperture, Lightroom, or Photoshop Elements), which groups them under one thumbnail, effectively.
I think what Bruce may be looking for is advice on how to compare multiple similar shots quickly. iPhoto has (had) a mode where you could show multiple images at the same time for easy comparison. Is there something like that in other apps?
You can compare multiple photos is one window in Aperture.
You can also use the Light Table functionality in Aperture, which will let you resize the pictures.
My way around the "view only hidden photos so you can delete them" problem in iPhoto is to have a "delete" keyword. Using a delete keyword also allows you to delete photos that you have selected in an album (normal behaviour would be to delete the photo from the album but not from iPhoto)