The Bushnell Back Track D-Tour is a great little GPS tool that is simple to use, yet full of features that I have really enjoyed using in a variety of contexts. Simply turn it on and go outside... the D-Tour will lock onto a number of satellites to fix your position. You can then set the clock, distance temperature and time units. Press the 'power' to set a location, such as your home. Then, when you are out on a walk, you can click 'home' and the compass will point in the direction you need to travel to get back home. You can also mark up to 5 locations.
The most brilliant aspect of this kit, in my opinion, is the 'Trip' facility. When in 'Trip' mode, the kit records your journey, noting the temperature and altitude as well as the route you take. It also displays your current speed and your average speed. Your D-Tour can then be simply plugged into the PC and your trip uploaded and overlaid onto a Google Map, with all the functionality you get from Google Maps. For every trip you do, the maps can be exported and the trip saved. Graphical representations of your trips are displayed at the bottom of the screen.
I have used this kit both for my own use and in the primary school in which I teach.