If you logged on to Facebook yesterday around 4 p.m. ET, you likely saw a preview of prototypes that were accidentally released for a short period of time. Users reported experiencing a revamped version of Pages, a new feature called Memories and the rollout of Questions, which it announced back in August. Shortly after the glitch, Facebook experienced downtime, later explaining: "For a brief period of time, some internal prototypes were accidentally exposed to people externally. As a result, we disabled the site for a few minutes. It's back up, and we apologize for the inconvenience."There's no word on when (or if) we can expect to see these features go primetime, but from yesterday's peek into the prototypes, here's what we know.Facebook "Memories"I joined Facebook in 2005 as a college student and since then have accumulated several hundred photos, messages and friends on the site. Memories appears to be an excellent addition to the site, especially for long-time users. Below is a screenshot that Inside Facebook picked up.Memories, which was accessible via the left-side navigation bar, categorizes your photos, status updates, friends, likes and events by year, making browsing your content on the site easier. Toggling between the categories appears easy, too. It is unclear, however, whether users will be able to browse friends' Memories. [Want more tips, tricks and details on Facebook privacy? Check out CIO.com's Facebook Bible.] [Slideshow: Social Media Haters Rejoice: Holiday Gifts Just for You]Facebook QuestionsBack in August, Facebook announced Questions, a feature that lets you propose a question to the Facebook community (which includes your Facebook friends and their Facebook friends) or propose a poll question. Below is a snapshot of Questions from Facebook's August announcement.During Facebook's glitch yesterday, I had access to Questions. The design of the feature is slightly different from the original snapshot above, since Facebook updated the design of Profile Pages a few weeks ago. Instead, Questions were accessible via the Share toolbar, where you can currently post a status update, photo, link or video.A Facebook friend of mine noticed access to Questions and proposed a poll: "Will you actually use Questions?" The poll appeared in my News Feed, and you were able to "follow" the question and receive updates when someone else submitted an answer.If you wanted to create your own Question or poll, clicking the Questions button would generate a form to do so. It also gave you the option to learn more about questions and polls, which took you to a separate page where you could browse numerous categories such as sports, science and technology, which broke into sub-categories that you could explore further.It appeared that many of the questions already asked and answered were from Facebook users in the United Kingdom.Facebook PagesTechCrunch reports that users experienced an updated interface for Facebook Pages, which mimicked the new Profile Pages design.Application tabs were moved from the navigation bar at the top of the Wall to the left-side navigation below the page's photo. The new Pages also featured lists of Facebook users (like you now have on your profile page), and there's a new button that lets admins "Login as Page." This lets you receive notifications for just your page, and not your personal account, TechCrunch says.The update to Facebook Pages and the preview of Questions don't come as much of a surprise. The sneak peek at Facebook's Memories prototype, however, would be a great addition to the site. What do you think about the prototypes Facebook released yesterday? Kristin Burnham covers Consumer Technology, SaaS, Social Networking and Web 2.0 for CIO.com. Follow Kristin on Twitter @kmburnham. Follow everything from CIO.com on Twitter @CIOonline. Email Kristin at email@example.com.