Found via a tab on the Facebook homepage, Live Feed loads up all of the stories from your friends and updates the list in real-time. The feed is available in Log Mode (seen above) or the more traditional Full Stories. When one of your friends does something, Live Feed slides everything down, making room for the new story, which fades in. The stream is very cool to watch roll down the screen and makes good use of the classic Web 2.0 AJAXy feel.
It's no secret that Facebook has been pushing its microblogging and life-streaming features to the forefront of the site recently. Facebook's "What are you doing right now?" feature is extremely similar to Twitter and its commenting system for news items is very reminiscent of FriendFeed. Facebook's implementation of Live Feed makes it a lot easier to watch what all of your friends are doing.
FriendFeed and Twitter are both very good at what they do, but have yet to gain the mainstream appeal that Facebook enjoys. Facebook is adding another feature that FriendFeed has long had and that has very similar functionality to Summize (now Twitter Search), so maybe it's time for them to start getting worried. By exposing its large user base to these features that FriendFeed and Twitter have perfected, Facebook poses a real threat.