Anyone who has ridden with me knows that I am directionally challenged ("Do we turn left here?") and I have been known to get lost on a ride or two (2008 MS150 ring any bells) so I now ride with my iPhone since it has a built in GPS and mapping software. Recently I downloaded the iPhone application for MapMyRide called iMapMyRide. You can find it in the App Store by searching for "mapmyfitness". Once this application is installed and an account registered (both free), you are ready to go. Before the ride starts, simply launch the application and start recording. When the ride is done, you will have a map of your entire ride. This map gets uploaded to MapMyRide.com and you can use it in the future to print turn-by-turn directions or at least sound a little smarter when your family asks you, "Where did you ride today?"
Here is the map I generated during last Saturday's training ride.