Facebook has been known to be planning some interesting location-based functionality for a while. But the full extent of the plans hadn't been revealed, until now.
It doesn't just record your location, it also grabs your altitude, heading and speed - perhaps to prevent some of the cheating that occurs on the aforementioned networks, where people driving along a road can check into all the places along it super-quick. However, for now it looks to only be launching on the mobile version of the website.
We'll bring you more as we hear it.