Jay Versluis

Once installed, head over to Appearance – P2 Header Ad and paste your ad code into the box.
Features:
<ul>
<li>preview your ad in the admin interface (see screenshots)</li>
<li>option to hide the ad for logged-in users</li>
<li>option to hide the ad for logged-in WP eMember users</li>
<li>works with and without a header image</li>
<li>option to show the same ad after the post content</li>
</ul>
I’ve optimised the plugin for a 468×80 pixel ad. Other sizes will work but may require your own CSS tweaks to make them look right.

P2 Header Ad

Works just fine! I'll use it for internal important notifications but definitely saved me some time for writing this feature myself :)

Nice!

Places a 468x80 pixel advert inside the header of Automattic's wonderful P2 Theme.

Thorsten Ott

Simple widget to extend P2s (and other themes) functionality and display recent @replies for a logged in user in the sidebar. 
It can be also configured to show direct replies to comments or posts without the @username indication.

Mention-Me Widget

11-year old plugin and it still works just fine! Sweet!

It works!

Simple widget to extend P2s (and other themes) functionality and display recent @replies for a logged in user in the sidebar.

P2 Header Ad vs Mention-Me Widget