Facebook product manager Andrea Vaccari updated the social website with news of a potential creep-fest new feature called Nearby Friends. As the name implies, Facebook will display your physical whereabouts to nearby Facebook friends, and vice versa. The good news is that this feature is completely optional.

"If you turn on Nearby Friends, you'll occasionally be notified when friends are nearby, so you can get in touch with them and meet up," Vaccari writes. "For example, when you're headed to the movies, Nearby Friends will let you know if friends are nearby so you can see the movie together or meet up afterward."

The service, which will roll out in the coming weeks, will allow users to choose who can see him/her when they're nearby, such as all friends, close friends, or specific friends on a list. Sharing with nearby friends goes both ways too: both Facebook members must approve the connection.

"If you turn on Nearby Friends, you can also choose to share a precise location with the particular friends you choose for a set period of time, such as the next hour," Vaccari writes. "When you share your precise location, the friend you choose will see exactly where you are on a map, which helps you find each other. Then you can meet up and spend time together."

That "precise location" also means that Nearby Friends users can see that you're out of town, so the only way to hide your whereabouts is to turn the Nearby Friends feature off. Honestly, friends don't need to see every exact location you're at, right?

"When you see a friend visiting a place you've been, it's the perfect opportunity to send a recommendation for a great restaurant," Vacccari adds. "You can also make last-minute plans to meet up with a friend who happens to be in the same place you're headed to."

Obviously, the intent of Nearby Friends is to help friends find each other offline. Vaccari was working on similar technology at startup Glancee before Facebook acquired the company in 2012. Vaccari grew up in Italy, and found it difficult to meet new people when she moved to the United States. She believes that more people will be willing to try out the new service when it involves their friends.

According to Mashable, Facebook was testing the feature with a "vast majority" of the company's over 6,500 employees for nearly 18 months. During that closed beta, Facebook used employee feedback to shape the service, and to sharpen the notification algorithm. At first the notifications were a bit excessive, and has been scaled back as the product evolved.

Vaccari says that the feature will adapt as it learns more about the user. That said, don't expect a notification to be made about a nearby friend if he/she never leaves the house because he/she pecks on a keyboard all day. The data Facebook collects is stored on the company's servers, but can be deleted by the user at any time.

Nearby Friends is opt-in because Facebook knows that many people fear data collection, and don't want everyone on Facebook to know where they physically are. "We are totally OK with people not wanting to opt in right away," Vaccari says.

Nearby Friends will be available on Android and iPhone in the U.S. over the coming weeks.