Do-it-yourself maps

For the most part, GPS manufacturers have a lock on the market when it comes to maps that can be uploaded to their receivers. GPS receiver owners must use proprietary maps distributed by the manufacturers.
However, a small group of technically adept GPS and map enthusiasts have found ways around this map monopoly. They have created free tools such as GPSMapEdit and Mapdekode with which Garmin GPS receiver owners can create their own maps and upload them to their receivers. Similar projects are under way for Magellan GPS receivers.
At the present, creating your own do-it-yourself GPS receiver maps is a somewhat complicated process, but a number of tutorials are available on the Internet. (Here’s one for starters:www.gpstm.com/eng/dekode_eng.htm.)
If you’re really interested in this topic, check out the Yahoo! Group devoted to GPS map authoring at groups.yahoo.com/group/map_authors.