If you have a Digital SLR and wish to have GPS coordinates associated with the images that you take, the JOBO AG photoGPS may be what you are looking for.
Digital Media Thoughts has information on the photoGPS which attaches to the hot shoe of your digital SLR and captures GPS information as you take pictures. The JOBO software then matches the GPS information stored in the photoGPS to the pictures after you upload them to your computer.
More information can be found HERE.