Facebook Places is an optional feature built into Facebook. Those who use Facebook on a smartphone can opt in to Facebook Places, which lets you share your location. By “checking in” to a particular location -- such as a concert, restaurant, nightclub or hotel – you’re knowingly revealing where you are to Facebook users. Perhaps you’re hoping a nearby friend will want to meet up for a coffee while you’re both by your favorite bookstore.

Similar to foursquare, Facebook Places uses your smartphone’s GPS to pinpoint your geographical location on the planet. Facebook also launched a related service called Deals, which lets you “check in” to find discounts or free giveaways from nearby retailers that participate in the program.

Revealing where you are isn’t for everyone, of course, and it can be a safety concern among parents who have tweens or teens on Facebook. You probably don’t want your child announcing to the world that she’s in the food court of your local mall. That’s why Facebook prohibits users under the age of 18 from displaying their location to anyone other than their Facebook friends.

When it comes to Facebook Places, remember this: It’s an opt-in service, since you need to manually “check in” before users can see where you are. If you want to use it, be sure to check your Facebook privacy settings and select who can follow your whereabouts, such as “Friends Only.” It’s also recommended that you disable the ability of friends to check you into places or “tag” you as being somewhere.