New: Facebook Places – Facebook introduces check-in feature similar to Foursquare, Gowalla

Social-networking giant Facebook has entered the check-in world.

Facebook executives on Wednesday announced the launch of Facebook Places, which — similar to services such as Foursquare and Gowalla — will allow people to use the GPS on their mobile phones to let friends know exactly where they are.

Facebook Places is available immediately in the United States through the latest version of Facebook’s iPhone app and, for other advanced mobile phones, through the company’s site for advanced mobile devices, executives announced at Facebook’s headquarters in Palo Alto, California.