Google Now, the personal assistant app for Android and iOS devices, is adding new reminders that nudge you at the appropriate time or place. For instance, if you create a reminder to buy milk and bread, and you happen to be in a grocery store, Google Now will remind you. And if you create a reminder to catch a train, Google Now will (figuratively) tap you on the shoulder and tell you it's time to head to the train station. It sounds both fascinating and maybe a little creepy. It'll be interesting to see how well mainstream users take to Google Now's assistant-like skills.