I just took the plunge and purchased a Jawbone UP for my 49th birthday. The idea is the little bracelet keeps track of how active you are (or aren’t) and reminds you to get more exercise. I was waiting for the Fitbit Flex to be released first, but now they are sold-out everywhere and have an 8 week waiting list. I was able to get an UP at BestBuy right next to Wayland, MA.
It just buzzed at me to indicate I’ve been stationary in my chair for 45 minutes. I’ve got to get up now and move around. I’ll be experimenting with the app and device the next few weeks and will report back how it feels.