Kyle Scheuerlein

Automatically turn all posts into excerpts of 300 characters and add a “Show More” link that will load directly in the page. If your post includes a picture, it will also obtain a thumbnail and place that at the beginning of the excerpt. Supports Infinite Scroll, too (assuming you manually enabled it on your P2 site)!
<ul>
<li>Shorter posts will be left alone, unless they have a picture</li>
<li>Posts with a picture will always be turned into a thumbnail/excerpt</li>
<li>Expanding or contracting a post will scroll to the top of the post</li>
</ul>
Planned:
<ul>
<li>Long posts with embedded video and no image include the video in the excerpt</li>
<li>Change the character length from the admin screen</li>
</ul>

Show More for P2

Works smoothly even on latest WordPress & Mercury child theme of P2.

Plug and play

Automatically turn all posts into excerpts of 300 characters and add a "Show More" link that will load directly in the page.

Annika Backstrom

The “Who’s Online” sidebar widget shows a list of recently-active 
blog users. It has been built with Automattic’s <a href="http://p2theme.com/" rel="nofollow ugc">P2 
theme</a> in mind, but does not depend on P2 
functionality.
The most recently active users bubble up to the top. After one week, 
users fall off the bottom of the list and are hidden until they return. 
As of this writing the list does not support live sorting; the user 
order is fixed, and users missing from the list due to inactivity will 
be added to the top if they come online.

Works as expected

Who's reading your P2 blog right now? Keep track.

Show More for P2 vs Who's Online