The Trails app is avaliable in the iTunes App Store. It will trace your movements in a smart way: you can interrupt the recording anytime, and resume the tracklog when moving on. Finished your trip? Upload the log directly to everytrail.com or bikely.com, or send it in email to whomever you like. You can even take geotagged photos with the standard Camera app, upload them to Flickr.com via email right from your divece, and import them to everytrail.com to illustrate landscape along your way. And it is still not all! You can even browse tracks at everytrail.com, download and use them instantly!
The sample below shows my favourite jogging lap.