Ever wondered how to find photos you took few years ago at the Disney World? Have you wanted to look at photos based on places you have visited, but didn't want to dig through your entire photo collection to find them? Organizing your photos by location, otherwise known as "geotagging," allows you to be able to find any photo based on the location where it was taken.
However, most digital cameras are not GPS-enabled, so location information must be added after the fact. In order to use the "Places" feature in iPhoto 09, you'd have to input location for each photo manually.