My photo is already geotagged. Can this information be used?
You have lots of geotagged photos with the exact geo coordinates? The respective coordinates are stored in the EXIF header of your files?

Great: So you don´t have to geotag your photos manually again!

The information will be read automatically when uploading the photo via the locr website, or the locr GPS Photo software. Your photo will be displayed with the exact position on the map. If you want to know more about the place where the photo was taken, just have a look at the Wikipedia articles which are also automatically assigned to the picture on the locr website.