The Garmin Vivofit ($130) is the latest in activity monitoring wearable devices. What sets it apart is that each day it sets a personalized goal for you, tracks your progress and lets you know when it’s time to get out of your chair. It does all this buy learning your current activity level and assigning you reachable daily goals. Each time you meet a goal Vivofit will adjust the goal for the next day. It also displays steps, distance, calories, and monitors your sleep patterns. You can even pair it with a heart monitor.