Next time when trying to find a bargain airline ticket you may get a little nudge from Google Now. A new card is showing up for some users that notifies you of price drops on itineraries looked up in flights search.
It appears (for now) to only interact with those who perform a search through Google's nascent flight-finding service. Like other Google now cards, you can turn it off if you don't want to see further updates.
Google Now is a particularly useful tool that mines your Gmail, search history, and other data to provide you with contextual information. It will alert you to traffic congestion, remind you of hotel check-ins, and offer articles to read.
Google keeps rolling out changes to the service, though they tend to be staggered as some get the new features long before others. If you don't see the new cards yet, just be patient and they will eventually show up.