Using the $2 Nike+ GPS iPhone app for tracking run distance and pace couldn't be simpler: start the Nike+ GPS app on your iPhone, drop the phone into your pocket, and start your run. Every kilometre (or mile if you prefer), your phone speaks your elapsed distance and current pace. At the the end of your run, it speaks your distance, time and pace, plays a congratulatory celebrity voice clip, and optionally uploads your run to the NikePlus.com website.
The app doesn't need or keep the phone display on – nor does the phone auto-locking interfere with the app's operation. After your run is completed, your route is displayed on a google map on your phone, and uploaded to the NikePlus.com website if you have that feature enabled. On an iPhone 4 retina display (960x480) the captured route is remarkably clear. The example map (click to zoom) is a screen capture off my iPhone after participating in the 2010 ArmyRun.ca 1/2 marathon last September. Update: 2011 Armyrun.ca: twitpic.com/6n0vxs
Compared to my aging (2003) Nike Triax Elite HRM/SDM (heart-rate and speed-distance monitor) watch, the Nike+ GPS app lacks a heart rate monitor function, and it doesn't work as well for indoor tracks if satellite reception is poor, as it must fall back to relying on the iPhone's accelerometer. My Nike Triax Elite, with its shoe-pod accelerometer, never uses satellites, but works well for me indoors and outdoors.
References:
- App Review: Nike+ GPS, Vlad Savoy, Sep 7 2010, engadget.com
- Both an alternative to and the precursor of the Nike+ GPS iPhone app, the
$30, Nike iPod 
Sport Kit is a small sensor (i.e. accelerometer) or shoe-pod. While select Nike shoes have a compartment for the sensor, 3rd-parties have developed a variety of clips and pouches to secure the sensor to the laces of any running shoe. A receiver included with the sensor plugs into the iPod nano as shown, but the iPod Touch (2nd gen or later), iPhone 3GS, and iPhone 4 have built-in support for the sensor – a receiver is not necessary. apple.com/ipod/nike
- The Nike Triax Elite HRM/SDM watch was state of the art in 2003 and included a heart rate monitor chest strap, a shoe-pod aka accelerometer which was secured to the laces of any shoe, as well as a USB-attached radio transceiver for downloading run data to your laptop and configuring the watch. manual.pdf battery.pdf software downloads
Updates:
- Update: Route of 2011 Armyrun.ca: twitpic.com/6n0vxs, benschmidt.com, Sep 18 2011
- How I Got in Shape with the Help of Technology, Adam Pash, lifehacker.com, Aug 16 2011