Social networking site Facebook introduced a new service called Facebook Places on August 20 that lets users share their location with others.
Facebook Places is similar to rival location-based services BrightKite, Dopplr, Foursquare, Google Latitude, Gowalla, and Loopt. It enables people to tag themselves at specific locations in much the same way you might tag yourself or friends in a photo you upload to the social networking site.
To use Facebook Places service you will have to download Facebook's latest iPhone application on your iPhone or head to touch.facebook.com on a HTML 5-enabled mobile browser.
For the moment, Facebook Places is only available to people living in the USA.
To "check in" (a term used to describe sharing your current location) tap on the Places button on your mobile and then press "Check In."
After doing so, "You'll see a list of places near you," explains Facebook in an August 18 blog post.
"Choose the place that matches where you are. If it's not on the list, search for it or add it. After checking in, your check-in will create a story in your friends' News Feeds and show up in the Recent Activity section on the page for that place."
While you are sharing your location on Facebook Places, you can tag friends who are in the same place as you. Facebook also lets you see a list of friends (and strangers) who have checked into that same location in the last couple of hours.
But what does this all mean for your privacy?
An August 2 report by market researcher eMarketer showed that despite users' privacy concerns about sharing personal information, two in five mobile users are tapping into their device's geolocation features.
"Worries about privacy and safety abound, but the cool-and usefulness-factor [of geolocation services] seems to win out," said eMarketer.
Up until now the majority of location-based check-in services have been frequented by a niche group of technology journalists and early adopters - market researcher Forrester believes only around 1 percent of adults in the US share their locations through geolocation services more than once a week - but with more than 500 million active users on Facebook across the globe that will no doubt change rapidly.
The USA and subsequent worldwide roll-out of the service (dates of which are yet to be announced) brings the longstanding debate about location-based privacy issues into the spotlight.
Given Facebook's tainted history of introducing services and privacy controls that blur the lines of what's public and private, users might be surprised to hear the company is working hard to make the overall introduction of this possible privacy nightmare a "positive process."
However, users should always keep their guard up when sharing information on the web, especially when it comes to sharing sensitive personal information such as your exact location.
And while Facebook has worked hard to bring geolocation services to the masses without causing a torrent of negative headlines, there are a few quirks you should be aware of when using the service.
As technology blog TechCrunch discovered, "you really don't have to opt in [to Facebook Places] before you can be tagged."
This means that unless you have opted out of Facebook Places (see link at the bottom of the page on how to disable Facebook Places) one of your friends can tag you in a Places post and your location will automatically appear on their wall.
This however, can easily be rectified by visiting "Things Others Share" in your privacy settings and unchecking the option that says "Friends can check me in to Places."
You might also want to opt out of the feature that shares your location with strangers who have checked into your current location by unchecking the enable button listed next to "Include me in ‘People Here Now' after I check in" - a setting that can be found in your Privacy Settings under the "Things I Share" heading.
If you would like to know more about using Facebook Places while ensuring you have the best privacy settings for you, The Electronic Frontier Foundation (EFF) has put together a user guide that explains some of the different privacy options available to you.
EFF's guide can be viewed here: http://www.eff.org/deeplinks/2010/08/how-protect-your-privacy-facebook-places
You can read Lifehacker's guide to disabling Facebook Places (and changing your privacy settings) here: http://lifehacker.com/5616395/how-to-disable-facebook-places
This article by CNET will also help you edit your Facebook Places settings: http://news.cnet.com/8301-19518_3-20014097-238.html
Facebook's Who, What, When, and Now...Where blog post: http://blog.facebook.com/blog.php?post=418175202130