I got one of these for my birthday.
It outputs NMEA format files, which I normally convert into the more widely used GPX files, using GPSBabel. Once I have my GPX file I use the excellemt GPSPhotoLinker to embed the GPS coordinate information into the EXIF of my photos.
We’ve just got back from a week traveling around Scotland. I ran the MotionX GPS app most of the time which produced a bunch of .gpx files. Which you can see nicely displayed on Google Maps below thanks to GPS Visualizer
We spent the day out in Rusilip and the surrounding areas, on the way back we thought it might be nice to stop and have a picnic somewhere, the park with the large mounds on adjacent to the A40 seemed as a good a place as any.
Googling for information about them reveals an interesting history. Being a bit of a geek and having a new GPS tracker on my phone I thought I’d walk up the spiral path around the middle of the three and see what the GPS trace looked like. After getting home and extracting the GPX file from Motion-X I found this brilliant site which enables you to upload a GPX track and have it overlaid on a variety of maps. The one you see below is a standard Google Satellite image, the colour of the track indicates the altitude.
As a bit of an asside, while I was descending the mound I had a quick look up on Geocaching.com to see if there were any caches near by, sure enough there is one on the Mound itself. It took a bit of finding however, as you can see from the photo it was getting a bit dark by then!