As you probably know from my other writings, I use iPhoto to manage my images. When I'm in that application, I can click on any photo, hit CMD-I, and get that image's metadata, including the exposure information. You can also retrieve the metadata in Photoshop, or even standalone metadata apps.
Even when I'm using a more simple camera, such as the Canon S-200, I like to know what exposure combinations produce my favorite pictures. This is helpful when I want to repeat the effect with another camera.