I bought a Fitbit Charge HR. It tracks my steps, calories in/burned, my heart rate (I have a mild obsession with knowing my heart rate at any given moment), water intake, sleep, pretty much anything fitness related.
I love it. I obsessively sync it. I constantly check its stats. I adore that it told me how many steps I took in the grocery store and how many calories I burned doing so.
This may not be a healthy toy for me, but it’s a fabulous one. Excuse me while I go for a jog.