We've previously covered quite a few different applications to geocode your photos. Geocoding or geotagging is the process of adding location information (latitude and longitude) to the EXIF metadata of your photos, so you can see where they were taken. RapidoMap is one of the newest of these tools and looks to have a couple of particularly nice features. The application integrates a browser for Yahoo Maps which is how you actually locate your photos on the globe. It has an iLife media browser that makes it easy to get your photos in, and a built-in Flickr uploader.
Best of all, RapidoMap is a free download from app4mac (points off to them, however, for using an installer package).