Summary: It is a cool idea but I do not recommend. After trying all the many different tips and tricks I could find in the manual and on the Internet I still could not get the sensor to connect to my iPhone. I purchased the sensor as I thought it would be fun and motivating but after the frustration of trying to get it to work I decided I would prefer to just go for a run - minus the headache.
Summary: This gadget thing is not accurate at all I run a mile in about 9.30 and it keeps giving me inaccurate distances. I recently did a 5K and at the end of it all it said I had done 1.94K Even after calibration
Summary: This will not work with an iPhone 4S. I took it to the mac geniuses and 3 of them couldn't get it to work. We tried everything in the book including several sensors. Many people are having the same problem online. I wouldn't suggest buying it. You can get the Nike+ app for free. Better app and gives you more info. So glad I spent $100 on Nike shoes when this garbage sensor does nothing.
Summary: I've used this product for a few years now but have noticed a decline in the quality of the sensor in recently (I've gone through 4 sensors). I just bought a brand new sensor to go in my Nike running shoes and have only managed to get the sensor to activate 3 or 4 times since (have done at least 20 runs during that time). It keeps saying 'walk around to activate sensor' and never actually links.
Summary: I spent several hours trying to get my brand new sensor to link to my iPhone. I kept getting the message to "walk around to activate the sensor". Finally I found a trouble shooting page on Nike Plus website with information that helped me solve the problem. USING THE TIP OF A PEN, PUSH THE SMALL BUTTON ON THE BACK OF THE SENSOR SEVERAL TIMES TO WAKE THE SENSOR UP. When the small button on the back of the sensor is PUSHED and HELD , it puts the sensor to sleep.
Summary: I have yet to get my runs to upload to the website and no ability to sync. Contacted the help desk but they just indicated that problems had been reported and they were working on it. Probably will go back to Garmin and excel spreadsheet. Tried to use the Nike + Running but I can run the same route and it will be off a mile from the day before. Same response from support desk.... problems have been reported. One star only to get it to post.
Summary: I do not need motivation to run or workout. I feel the IPod Sensor is very inaccurate. On my first calibration attempt i walked a mile, and the sensor read .13 miles. the most i could calibrate it at was .35 so i did the best i could. I then ran a mile at an average pace, and it said I ran less than a half a mile. I calibrated it to .75 which was the most it would let me at the time. Since then i have been able to calibrate it to the distance i run.