Keith has had the Nike Plus for a few years now. His enthusiasm goes in waves; sometimes he uses it religiously, and other times (probably when he's not training as hard) he can take it or leave it. When he does use it, he really enjoys uploading his runs and tracking the stats about how far he ran in each month, when he ran fastest and slowest during each month, etc.
Knowing of his interaction with the Nike Plus, an article on Wired caught my eye the other week, titled "The Nike Experiment: How the Shoe Giant Unleashed the Power of Personal Metrics." The article discusses how seeing and analyzing the workout data motivates people to keep going. In particular, I found the reference to the Hawthorne Effect, where workers performed better just because they knew they were being watched, fascinating.
I would say that this blog is a form of the Hawthorne Effect. I put it out there to the world when I have running or weight loss goals, or all of my various New Year's resolutions. And whether anyone happens to read the post or not, I think I'm being watched, so it gives me motivation to keep to my goals.
I don't think I want to get a Nike Plus; I already have the desire to run. Maybe I need to get something that counts calories as I consume them, and then tweets them out to the universe. Or have surveillance cameras installed in the kitchen. Just the thought makes me shudder!