Google’s free photo organizer and editor Picasa is a great way to organize, tag, and lightly edit your photos. The price is right (free download from Google) and (due to its open plug-in structure), it is easy to customize. Lifehacker editor Gina Trapani has an excellent article about some of the available plug-ins and mash-ups, including flickr integration, simple web albums, and geo-tagging with Google maps.
Geo-tagging allows you to assign a physical location to your pictures and lets others browse them while looking at a Google Map of the area. It’s a cool way to see how others view and shoot an area that you may have photographed. For a great introduction to GeoTagging, go to Digital Outback Photo and read their handbook on the subject.