If you’re using a high-end Nikon digital SLR (D200 and above), the simplest method of adding lat/long coordinates to your photo’s EXIF data is to use the MC-35 GPS adapter cable, which has a port for a GPS receiver’s serial cable. (The Nikon web site only lists the cable as being compatible with the D2-series pro cameras, but Chet reports that it works with a D200.) But the cable seems to be hard to find and is moreover a little bit expensive ($120+). A do-it-yourself alternative has been cooked up by Chris Harrison: it’s much less expensive, but you’ve got to be comfortable with circuit diagrams and breadboards. A different DIY project involves stuffing a GPS module into the MC-35 itself — not cheap, but more compact, and again not for the timid. Via Ogle Earth.