NEW YORK — Facebook users carrying their smart phones will soon be able to "check in" to real-world locations such as bars, parks and live concerts as the social network makes its first foray into the location services craze.
"Where are you?" is joining "What's on your mind?" as Facebook lets its users declare their whereabouts to their friends and to people nearby.
With the launch of Facebook Places, the world's largest social network joins a growing number of services that let users find coupons, earn quirky merit badges or simply share with friends where they are.
These location services from startups including Foursquare and Gowalla have grown in popularity with the widespread availability of smart phones that have GPS and other means of determining the user's location.
Facebook's version will initially work through the site's iPhone application; users will need to download a free update of the Facebook app.
Owners of other touch-screen gadgets will be able to get the feature through visiting touch.facebook.com on their mobile Web browsers. Facebook says it will add Places to other smart phone apps later.
As with any new Facebook product, there are privacy concerns.
However, following flaps created by earlier launches, "Facebook seems to be taking a more moderate approach to location sharing," said Jules Polonetsky, who co-chairs the Washington-based Future of Privacy Forum.
By nature, check-ins are "opt in" — that is, you won't be forced to check in to a location if you don't want to. When you do, your check-ins will be shared with your friends by default, but not with the broader public unless you decide to do so.
If you're out and about with friends, you'll be able to "tag" them using the "at" symbol (@). Your friends will then be notified that you have tagged them and can choose to check in, too, or reject it.
A feature called "Here Now" will let anyone who has checked in to a place see who else has done so. Other Facebook users who have checked in to the same location will be able to see you even if they are not your friends, but you can turn this feature off.
Though they are still new, location services present "endless possibilities" to businesses, eMarketer analyst Debra Aho Williamson said.
"Marketers want to reach consumers when they are at the point of making a purchase decision, and location services offer that opportunity," she said.