Price: $68

Fitness buffs are secret technology buffs under all of that lean mass, but it makes sense. Fitness aficionados are constantly reading up on biology and nutrition, so they do have some scientific interests. Now, most of them are obsessed with the Fitbit. It’s also an experiment in social media—you can share your activity, like counting your steps, how far you’ve traveled, and how many calories you’ve burned, so that your friends can hold you accountable.