I have been doing WW for a month now but felt unsure of the activity points being accurate. I broke down and bought a heart rate monitor. I am so glad I did.
What a motivation for me I wish I had gotten one sooner.
I had an Omron HJ-121, I was given an Ipod Nano for Christmas so after reading the raves at the WW forums I splurged also on the Nike+. Does anyone here use the Nike +. I know some at the WW forums are on their own challenges with the nike+ keeping track.