Hello there!
Dashometer is an elegant and accurate GPS dashboard, speedometer, and navigation tool.
http://itunes.apple.com/app/dashometer/id361241002?mt=8
This App provides an easy to read -- and flexible -- display of GPS data. As a GPS dashboard/speedometer -style App it has somewhat unique features compared to similar Apps; these features include alarms, bookmarks, and the ability to export KML and GPX data.
Dashometer is consistently highly-rated, and is pretty frequently updated in response to customer feedback.
A video walk-through (of a slightly older version) is available here:
http://www.youtube.com/watch?v=SnDO2Kt9rpI
An iMovie trailer ;-)
http://www.youtube.com/watch?v=MXU2mN-Bz7M
http://www.flickr.com/photos/ianjray/sets/72157625230522610
http://www.ianjray.name/dashometer/
Enjoy :-)