During my outdoor activities I often (not to say always) carry a Garmin GPS device with me. Nowadays current Garmin devices record also heart rate, pedal cadence or even temperature and write these data into a GPX file as extensions.
After my last cycling trip I edited (like I normally do) my tracks in viking, when I realized that all the additional Garmin data are lost. I tried to find another workflow without losing the data in the GPX extensions. Finally OGR was once more my big saver. For the following workflow OGR is required at least in version 1.8.