GPSTrack allows you to use the GPS receiver in your iPhone or iPad to show your current location and create a log of your travels, showing you a map of your path, updated in real-time.
GPSTrack can track your location while in the background, so you can continue to use your iPhone for other tasks. (Continued use of GPS running in the background can dramatically decrease battery life.)
Saved tracks can be exported via e-mail in GPX and KML formats, useful if you want to geotag photos from a camera that doesnt have GPS support.