GPS

This is my new toy, some would say it is "non-essential". I would vigorously dispute that, although umm, I haven't used it yet ...

It's a Sony GPSCS1 and what it does is create a log recording the time and location from GPS satellites. When you are back at your computer you download this log and using some software, match the info with the time data on your photos.

The result, photos with the GPS coordinates merged into the photos EXIF information, which then allows you to accurately map where the photos were taken.

I am sure you'd agree, definitely essential!