Spontaneous get-togethers are now more possible than ever with Facebook's new Nearby Friends feature. You'd think parents could use it to see if their kids got where they said they were going, but Nearby Friends is only available to Facebook users aged 18+. And then it's "opt-in" – not on by default – so sharing location has to be a conscious for adults who use it, and they can only share with … [Read more...] about Facebook’s new friend-tracking tool