Yesterday Tumblr founder David Karp wrote that he and his girlfriend were going to try wearing Fitbits during sex so they could calculate their physical exertion. Get ready for the brave new world of truly constant life-updating.
You wear your Fitbit somewhere on your body—"on your waist, in your pocket or in your undergarments." (That'll be a fun surprise for a new beau!) It tracks your physical activity and calories burned, even while you're sleeping, and syncs up with a base station using similar technology to the Nintendo Wii. You can input the food you've eaten on the Fitbit website and then it calculates how many calories you've burned, or not, that day.
It costs $99. I have not yet used one. They are currently taking pre-orders that will (supposedly) ship February 17. But I'm envisioning some horrible future feature where you can automatically update your Fitbit status to your Twitter or Facebook or whatever, and then my dashboard becomes filled with "I just ran 3.2 miles and burned 407 calories using Fitbit!" Or "I just fucked my girlfriend for 27 minutes and burned 200 calories using Fitbit!"