There’s an interesting article on Terry White’s Tech Blog about his experiences using the Sony GPS device for digital cameras. The concept seems simple and the implementation very easy, but reading the article and associated comments I’d be a little concerned about the GPS unit’s ability to pick up a correct signal.
A couple of alternatives are mentioned in the comments. Specifically the GisTeq PhotoTrackr and the Jobo PhotoGPS. I’m following up with both these companies as this is definitely something I want to purchase. When I do, I’ll be sure to post my experiences here.