GPS speed sentry. it is a small program cost, $15 but is great. i use it for bicycling, it will record speed and elevation, and put all of that into a graph.
I have it running on my own custom 6.1, and it works fine, so im sure it willl work for you. check out the link, it is a great product for a great price.
http://www.pocketgear.com/en_US/html...id=prod5660576