Nike+ consists of a sensor that goes under the insole of a Nike+ shoe or can be used in a pouch under the laces of other brands of shoes but apparently placement is critical so the shoes produce the best results. There is also a receiver that plugs into an iPod (Nano, Touch or iPhone). You then calibrate the sensor to your stride, enter your weight and the iPod can give you tons of information about your walk or run including distance, time, average pace and calories burned. One of the neat features is the ability to set up a "Power Song." When you press the center button, the selected song overrides the playlist. The idea is to bring up a particularly motivating bit of music for when your energy begins to wane.
It really gets interesting once you sync the iPod. It uploads the data to Nike Running. At this website it tracks ALL manner of data about your run, including information regarding the terrain, weather and how you felt. The information can then be displayed in any number of ways including a very spiffy chart of your speed over time. The website also gives you the ability to set yourself goals in calories burnt, miles run or number of runs completed. It can post some of this information on your Facebook wall or into your Twitter feed. One of the more cute bits of feedback is your "mini." It's an avatar that you create at Nike's website that gets more animated as you run more...and it can be added to your Facebook profile. The website also contains a coaching segment that will give you a training regimen from a novice "Walk to Run" workout up to full blown Marathon runner training. There is also a section for setting up online Challenges to participate in running programs with a huge online community or something with a group of friends.
It's worth noting that when I say "run" the device supports walking just as well.
At the $30 retail, this is a bargain if you walk or run for exercise BUT one word of warning!
Do not buy this thing mail order. The support is virtually non-existent and DOA sensors happen from time to time. I'll also save you a day of grief and regret that I went through. If the device starts losing your pace, coming up very short on your walks or runs and refusing to calibrate, return it. There really isn't anything to be done in the way of fixing and you need a new sensor.