As expected, Facebook's made a major overhaul of the site, in a move which has been largely welcomed by analysts and privacy campaigners.
The biggest visible change is the addition of a new feature, Groups, which allows users to split their acquaintances into various sets - potentially averting those horrible situations where your boss sees exactly what you got up to with your friends last night.
"When a group member posts to the group, everyone in the group will receive a notification about that post," says Groups engineer Daniel Chai.
"Now I won't have to guess anymore about whether my parents saw the pictures I posted of their grandkids; when I post in my family group, I'll know that they've been notified about it and that only they will see it."
The default setting for a new group is 'closed', allowing non-members to see the topic but no other information. However, users have the option of changing this to 'open' - visible to any member of the public - or completely secret.
The addition of Groups has been welcomed by privacy organizations.
"Notably, rather than setting the default for new groups to 'Open' - where both group membership and content is public - Facebook has wisely set the default group privacy level to 'Closed', meaning that although group membership is public, the content shared within the group is only available to group members," says Kurt Opsahl of the Electronic Frontier Foundation.
"Facebook has also provided an even more private option: 'Secret' groups, where both the membership list and content are only available within the group itself."
But, says Opsahl, the company should go further and add another category of Groups: anonymous. "There are many people, such as violence survivors or HIV positive individuals or religious groups, who may want to have a group discussion without revealing their identities," he says.
And some observers are concerned that the Groups feature will make it easier for teenagers to keep their parents in the dark about what they're really getting up to.
Two other new features were also announced.
Users can now download everything they've ever posted to the site as a ZIP file - a great resource for autobiographers, says the company.
And there's now greater control over the data accessed by third party applications, allowing users to give or deny permissions on a case-by-case basis.
"We've heard loud and clear that you want more control over what you share on Facebook - to manage exactly who sees it and to understand exactly where it goes," said CEO Mark Zuckerberg.
"ith this new Groups experience and the other tools we're rolling out today, we're taking a few important steps forward towards giving you precise controls."
Erica Newland of the center for Democracy and Technology said the group welcomed the changes, which she described as an 'about face' on privacy.
"Perhaps, given rumored reports of a Google social product, Facebook is recognizing that success in the online marketplace requires remaining competitive on privacy," she said.
"Regardless of the motivation behind them, these changes are a huge win for consumers and the company alike. Facebook has positioned itself as a privacy innovator and we urge other companies to follow its example."
And Augie Ray, a social networking analyst with Forrester Research, said the moves show that Facebook has transformed itself and is finally committed to transparency and user controls. He added that Zuckerberg made the announcements with more passion and conviction than ever before.
"The Facebook that announced Facebook Places and Groups seems a more seasoned and trustworthy organization than the Facebook that announced Beacon and Instant Personalization," he said.
"Gone is the talk (or implication) that privacy is no longer a social norm, and instead we now see a company that recognizes it cannot afford to push the envelope too far."