GPSBabel

You won’t find any standards when it comes to GPS receiver waypoint, route, and track formats. Each GPS receiver manufacturer seems to have its own data format. To further complicate things, software companies that make mapping programs also use their own data formats. This can make exchanging GPS data between different receivers and software a very big challenge.
In order to help address this, the folks at topoGraphix (www.topographix.com), a GPS and map software company, developed GPX. GPX stands for GPS Exchange, which is a lightweight, XML (eXtensible Markup Language) data format for exchanging waypoints, routes, and tracks between applications and Web services on the Internet. GPX is slowly building up momentum and is being adopted by both software vendors and Web service providers. However, until a standard is widely adopted (and I’m personally not holding my breath), your best bet to exchange GPS data is the free GPSBabel utility. This versatile program converts information created by one type of GPS receiver or software program into formats that can be read by others. GPSBabel is available for a number of different operating systems as a command line utility, and you can find easy-touse Windows front-ends if you prefer a mouse and menus.
To get more information about GPSBabel and download the utility, visit http://gpsbabel.sourceforge.net