This morning I got to talk to an AP Computer Science class at a local high school about GPS receivers, and the wonderful world of geospatial data. We touched on making your own maps, Google Maps/Google Earth mash-ups, and the kinds of data you can get from the internet and from a GPSr. Fun stuff.
In timely fashion, Scott has some info on how to geotag your photos using various means, which is handy information for the geospatially inclined.