Aperture - Import Locked Photos
If you flag or lock photos in your camera during a shoot, you can selectively import these photos into Aperture. During an outing last weekend, I previewed the shots in my Nikon and locked a few of them because I knew they were images I wanted to work on first.
Once back in the studio, I did a two-pass import into Aperture, taking advantage of Aperture's File Types when importing. I first imported only the flagged/locked photos into a new project, adding an Aperture flag to them all. The second import pass brought in the rest of the shoot. The end result - a new project where I can easily find the images I'd locked in camera.