The Web's largest social networking site added Deals, along with improvements to its Groups and Places tools, to its free applications for iPhone and Android. Facebook made the announcements during a press event at its Palo Alto, California, office.  Smartphone app developers will be able to implement a tool called "single sign-on," which allows users to log in to third-party mobile apps using their Facebook accounts and connect with their networks of friends there. Reps from FarmVille maker Zynga, Game Network and daily-deal provider Groupon took the stage to say they would support the feature in their apps.  Facebook has offered something similar in Connect, but single sign-on makes the process easier. The system recognizes when someone is signed in to the Facebook app on their phone and can use that information in other apps.  "No matter what environment you're building on, there will be people there," Facebook Chief Mark Zuckerberg said of the new tool.  Erick Tseng, a former manager of Google's Android project who now leads Facebook's mobile division, demonstrated single sign-on at the event.  "It removes the need to ever have to type in a username and password ever again," Tseng said. "No more forgotten passwords."  As long as you don't forget your Facebook password.  Zuckerberg said 200 million people are actively using Facebook on their phones. That's more than a 200 percent increase from a year ago. Addressing a persistent tech rumor, he said Facebook is not making its own phone.  With the new Deals feature, Facebook users can see at a glance on their smartphones a list of merchants nearby that offer coupons. Check in to that store using Facebook's Places button, show the clerk your phone, and you can score that offer.  The service can also alert you when a store close to you has a coupon. Facebook the company does not take a cut of deal listings.  The new versions of Facebook's smartphone apps include new Places features, such as easier ways to tag friends during or after a check-in.  "It's one thing to say where you are," Zuckerberg said of the crowded arena of location-based social networks, including Foursquare and Gowalla. "But it's a whole lot more interesting to say where you are and who you're with at the same time."  Zuckerberg declined to comment about a frequently requested Facebook app for the iPad. "iPad is not mobile," he said, somewhat testily. "It's a computer."  A minute later, he adopted a gentler tone.  "Sorry, I didn't mean to be rude to Apple there. We all love Apple," he said, adding that he was trying to keep the event focused on Wednesday's announcements.  Zuckerberg acknowledged that development of its Android software has lagged behind that of its iPhone app. But the two now seem to finally be in sync, he said.
Connecting with friends is great, but Facebook will soon help you score a free pair of pants.Facebook on Wednesday began offering coupons from various retailers, including a promotion from Gap which