Linking your GPS to your PC. This enables you to enter cache locations direct from your PC (instead of laboriously entering the co-ordinates by hand) and record your journeys for later processing. Almost all GPS units can be linked to your PC with a suitable cable. Some can only link via the serial port conector while others link via the USB connector. You will need to buy the appropriate cable from your GPS supplier. In my opinion the best program for simply linking your GPS to your PC is the excellent G7ToWin program from Ron Henderson. There is a good help file available for download and the program enables you to use cache locations downloaded from geocaching.com as .loc files which are available without paying a subscription. Download this excellent program from the G7ToWin page. (On the same page you will find G7ToCE which allows you to store your GPS data on your PDA.)

Using Maps To really enjoy geocaching with your GPS, a program that allows you to display maps and plot your route and caches is a great idea. Without a doubt, the best program available is OziExplorer. You can display your map, download the cache location from geocaching.com and display it on the map, plot a route and then download the route and cache location to your GPS. Print out a copy of your map and off you go! Then when you return home, use OziExplorer to download the track recorded by your GPS and plot it on the map again to see where you actually went! The freeware version of OziExplorer has some limitations but is very useable. When you download the free version you also get a trial version of the full package which can be used to see what you are missing in the free version. I recommend you get the free version working first, and try it out on a couple of caches. Then try the trial version to see what you get in the paid version. My guess is that once you have done a few caches you will decide to spend the £55 it costs to buy the full version. Money well spent. But first, download the free version.

3D Maps There is an add-on for OziExplorer called OzExplorer3D which allows you to go one step further and create 3-dimensional maps showing the route you plan (or the route you took, or both). You need a map and the altitude data for the region of the map. This altitude data can be obtained free from the internet and full instructions are given in the tutorial included with OziExplorer3D. I have produced a small example of the output from when I went to the Cruz de Juanar just outside Marbella. You will see that I turned back just before reaching the top. This was owing to bad weather, it was actually snowing!.

Linking your digital photos. Photos taken with your digital camera include a lot of information about the photo, hidden in the jpg file that the camera produces. This data includes the excat time and date of the photograph (assuming your camera clock is correctly set!). The data from your GPS records where you were at each moment and so if you could link the two, you would know exactly where each photo was taken. Happily, there is an add-on to OziExplorer that does just that! It is called OziPhotoTool and you can find it on Alistair Dickie's OziPhotoTool page. It's free for non-commercial use.

More advanced stuff There are many add-ons for the OziExplorer program and lots of information about the subject can be found by searching the web. However, to make your life easier, almost everything of interest can be found on Dave Patton's website. He also has a wide range of other useful information on GPS and maps on Dave Patton's home page. You should also check out the Optional Extras link on the OziExplorer site.