That is a pretty nifty thing. But our digital camera doesn't have a GPS receiver on-board. And we do tend to take a lot of pictures while geocaching -- wouldn't it be cool if we could add markers with pictures in the maps we make?
The GPSr creates a tracklog: a position along with a time is recorded in the internal memory, and that is used to create the map. And the digital camera records the time the picture was taken in the EXIF header... So if you combine those, you know where the picture was taken! (At least, if me and klik we're too far apart at that time...)
Brilliant in its simplicity.
There is quite a bit of software that does all this. gPicSync is made by Google, released under the GPL, and has both Windows and Linux versions available. I'll be researching this a bit further in the next week.