Adobe Photoshop, Adobe Bridge, iPhoto, played a bit with Lightroom and Aperture
My workflow is first get the images from the camara into a folder with the date/dive site as its name - such as 2007_01_24_TheCoolReef, and before I do anything else, make backups immediately. Usually when I travel I have a laptop and some portable drives and blank DVDs/CD-R to burn.
Then I usually bring into iPhoto or browse through Bridge/Photoshop
iPhoto is easy and quick to take a look at what I have then start looking at what may be keepers. In iPhoto you can quickly “star” the ones you like and create a smart Album to have the shots you like organized - then move those out to a folder on a computer for editing.
The one thing I do is never delete a photo either in camera or afterwards. Sometimes I may miss something the first go round, and even if a shot is not good for whatever reason, going back from time to time and looking at why the shot was poor is a good tool to learn from. And with hard drives and other media being less expensive everyday, not a big deal to keep them.