[Ben E Lou]

So is there a way to get a GPS device that connects to the iPhone that makes apps like RunKeeper actually accurate? For today's run I used multiple apps to measure as a test and got these results:

RunKeeper: 4.36 miles in 44:50
MapMyFitness: 4.44 miles in 44:49
Strava: 4.5 miles in 45:15
Polar Beat: 4.46 miles in 44:50

I also hooked up my Polar GPS watch that uses satellites, so totally independent of the iPhone. It said 4.11 miles in 44:43. I then took our new-ish (bought brand spanking new 6 months ago) car on the same route and it measured 4.1 by the odometer. That car also has a Garmin GPS that came up with 4.1, so I'm feeling pretty confident that the 4.11 from the Polar GPS is correct. But is there a device similar to it that uses satellite triangulation (and doesn't cost me a small fortune) that will, for example, make the Runkeeper chick tell me the *correct* time and speed??? I guess I'm saying I want something will override the iPhone's internal GPS in one of the apps. Does that make sense, and does such a thing exist? If not, I guess I can just use the watch and look down at it, but I'd prefer not to have to do that...