There's a good introduction to FriendFeed in an article featured in the Business section of today's New York Times – "Service Helps Friends Share Their Online Discoveries".
I read the article early this morning and went and signed up for a beta invitation – Bret Taylor sent me one about an hour later and so I created my profile and started to test drive FriendFeed.
I think this is a great idea but needs an addition – let me create separate feeds of what I find interesting for groups of my friends. This would a great tool for sharing research, stream of consciousness etc. with a group of like-minded friends or business colleagues.
It would also be nice to have the ability to tag a page into a feed without having to use Digg or one of the other services that FriendFeed tracks to extract your interests. In some respects, FriendFeed reminds me of Ted Shelton's PersonalBee (now a part of Technorati) that allowed an "editor" to create a feed of information that could be reviewed by subscribers.
There's a fantastic amount of information out on the web but having to share it via email links is hard work and doesn't lend itself to group conversations. I think FriendFeed is a great step in the right direction.