OkMap is an unusually powerful (yet also free) GPS and mapping application.

The program can import maps in more than 30 formats, including GFW, JGW, PGW, TFW, BPW (World file); ECW (Earth Resource Mapping); GeoTiff; MAP (OziExplorer); IMP (CompeGps); GMI (GpsTuner); SHP, DBF (Esri shape file) and DCW (Digital Chart of World), along with many image formats. And it can interface directly with Google Earth and Google Maps.

Wherever the maps come from, you can then work with them to create waypoints, routes, tracks and more. These can then be uploaded to your GPS device, or you can alternatively download information from your GPS and display it on the maps. (OkMap works with all GPS devices supported by GpsBabel.)

These map additions can be static, so for instance you might create a list of photos which are displayed on a map, so you can see exactly where they're taking.

But OkMap can also do much more. If you run the program on a laptop with a connected GPS, say, then you can plot your position on a map in real time, and send this information constantly to a remote computer. So a group of people, all equipped with OkMap, laptop and GPS, could see everyone's position updated in real time.

And even this is just the start, but we simply don't have space here to do the program justice. So if you're at all interested in maps or GPS then download the program and try it out, or check the OkMap site for more information.