Fitbit
So I got a new fitbit so I passed mine down to Stellan (which, if you've been following my status updates with an unlikely degree of rapt attention, you'll recall was itself a hand-me-down from Emily to me. We're a wearable-computing kind of family, we are.)
Predictably his daily step count is routinely double or triple mine. He lags only slightly behind the two friends who were training for Saturday's half-marathon. This is all well and good and only a tiny bit demoralizing