Where were you last Wednesday at 7.30 PM? If you carry any Android phone or tablet, Google now can automatically figure out where you work and warn you about traffic.
Google launched the first version of this tool around the same time that they launched Latitude. After they killed latitude off, they kept their location browser around, polishing it up and adding new little tricks as time went on.
It’s mind-blowing to think about how much data they’re gathering, if you’re suddenly realizing there’s location or two that you’d rather weren’t sitting in your history, you can wipe it on a day-by-day basis or clean your entire location slate in one fell swoop.