1.
Prologue
wordpress.org/extend/themes/prologue

2.
P2 Likes
wordpress.org/extend/plugins/p2-likes
P2 Check In
wordpress.org/extend/plugins/p2-check-in
Mention-Me Widget
wordpress.org/extend/plugins/mention-me

3.
P2 Resolved Posts
wordpress.org/extend/plugins/p2-resolved-posts

4.
Markdown for P2
wordpress.org/extend/plugins/markdown-for-p2

5.
wpcandy.com/teaches/how-to-manage-a-proper-multi-author-wordpress-blog
woothemes.com/2009/08/real-time-productive-communication/#comment-24889
woothemes.com/2009/08/real-time-productive-communication
ma.tt/2009/05/how-p2-changed-automattic
make.wordpress.org/core

6.
p2theme.com

7.
wpmoscow.wordpress.com