(CNN) -- Facebook fans are getting a new toy this week. With the launch of Facebook Chat, users will be able to communicate in real time with friends on the site.
The social networking giant, which boasts more than 69 million active users, has always had a built-in message system that resembles e-mail.
But for the first time, the site will release a chat system so friends can type back and forth instantly.
Because Facebook users already have lists of friends, they won't need to build buddy lists. At the bottom right of any Facebook page, users can click an "Online Friends" button that will indicate which friends are available to chat.
Facebook Chat only allows for one-to-one conversations. Users will be able to view recent conversations, but the chats won't be logged permanently, and users will be able to clear that chat history any time.
Facebook users will also have the option of keeping the conversation on the bottom of the screen or creating a pop-up window they can move. A chat window will also display Mini-Feed stories, which are notices concerning other friends' Facebook activities.
Facebook Chat could mean big competition for America Online's instant message client AIM, which is the No. 1 instant message service in the United States. (Time Warner is the parent company of AOL and CNN.)
"[Facebook Chat] looks like it's going to be an interesting and useful feature," said Josh Pasek, a graduate student in political communication at Stanford University. "My bet is that this will surpass [Google's] GChat as No. 2 behind AIM, because it's so universally used and logged into."
Patrick Thornton, who runs the blog "The Journalism Iconoclast," said since he can chat with his Gmail contacts in Gmail and Facebook friends on Facebook, he will have little need for AIM.
"Facebook is a platform that allows people to connect in much deeper and more visceral ways than a standalone IM client ever could," he said. "Why just talk to someone when you can experience them? That's what Facebook allows people to do."
While AOL was "the original social network," as a standalone instant message client it will become less popular, he said. AIM only allows for message exchange and file exchange, while services like Facebook combine instant messaging with other features.
But AOL spokesperson Erin Gifford pointed out that Facebook users have been able to incorporate their AIM accounts in their Facebook profiles since autumn, and millions have already done so. With this feature, a user can click on a friend's screen name from within a Facebook profile to open up an instant message window in AIM, and also see a user's AIM online status in the Facebook profile.
"We believe that AIM users will continue to use AIM within Facebook and from wherever they are on the Web and on the go," Gifford said.
Facebook Chat's release comes just weeks after AOL acquired Bebo, a social media network that boosts AOL's total network to 80 million unique users worldwide, the company said last month.
"Big companies see a lot of value in a social networking site for the ability to tap into a group of users where, like on Facebook profiles, people are putting their interests," said Corey Hulse, a technology consultant in Philadelphia. "It's a trend of Web sites wanting to continue to find the next big thing."
A spokesperson at Facebook declined a request for comment.
Facebook's rival MySpace, purported to have about 110 million users, already has an instant message system called MySpaceIM.
While third-party applications have emerged to enable chat between Facebook users, Facebook Chat is the first official, Facebook-wide chat system that will automatically appear on all profiles.
As with any new online feature, privacy concerns will abound with Facebook Chat, users said. While a user can elect to appear offline, there is no way to block another user from chat.
Hulse, who uses Facebook once a day, noted Facebook has been generally responsive to criticisms and concerns from users.
One Facebook user, Russell Beaumont-Ede of Exeter, England, said there will always be privacy concerns with any Web site. But he added, "I believe that this feature has been developed over a long period of time, which to me would ease any concerns I have."
Facebook Chat adds to a plethora of instant messaging services, which means if a user's friends chat on different clients, it gets messy to see everyone online at once. An Internet user may get bogged down trying to juggle conversations on AIM, Yahoo! Messenger, MSN Messenger, Gmail and Facebook.
"Not only do I need to keep each of the IM programs open now, but I also need to keep a copy of Gmail open in my browser, and now a copy of Facebook open in my browser," said Gil Varod, a computer programmer based in New York. "It's not like I need five different e-mail programs open to e-mail five different people."
Varod's solution is to use programs like Digsby or Pidgin, which consolidate buddy lists from multiple instant messaging services and enable communication with anyone in any of those services. He said he hopes someone gets Facebook Chat working on one of those programs because instant message client companies "haven't figured out how to play nicely" and make their services more interoperable.
Facebook began rolling out the chat system Sunday, and only some networks have been added so far. Pasek said he could chat with friends in the Stanford, Berkeley, Harvard, Yale and Brown networks as of Monday.