"It's like a videogame. I have such a competitive personality, so I'm going to beat these people today."

Says Carrie Mundy, "a stay-at-home mom and photographer in San Diego [who] bought her Fitbit in February."

She says she is regularly hitting 15,000 steps a day and has already lost 4½ pounds. To accumulate more steps, the 36-year-old says she walks down every aisle in the grocery store and makes extra trips back and forth when folding and putting away her laundry.

Ms. Mundy says her Fitbit also motivates her to get out and walk. "I'm constantly chasing these two people who I haven't caught up to," she says, referring to two friends whose total number of steps she can view on her device's display screen.

Is this good, because you can keep score and exploit the mental energy that comes from seeing something that you want to do as a game? Or is it bad, because natural life is replaced by game playing? Where's the joy? Should you be walking down every aisle in the store to rack up more steps on some electronic device? Do you lose the normal motivation for doing things? When is an electronic device cool and when is it making you weird in a way that would cause you to seek treatment if you did these things without the device?

ADDED: If you want this device, here it is.