codersempire

Yahoo! Status Checker is a simple plugin which you can use on your wordpress websites as an new feature or advantage for your users with the ability to check if the particular yahoo user is online or offline.

Yahoo! Status Checker

Yahoo! Status Checker by Techya.Check any yahoo id to see if he is online or not.

bartschatten

This plugin will display the online/offline status of defined server in your sidebar. 
This idea was born in case of setting up dedicated trackmania servers and 
I want to show the actually stats for the blog visitors / clan members. 
The plugin is easy to configure and easy to use. Now with Trackmania colorcode support. 
See installation section for more information.
Check out http://www.martin-fredrich.de/wordpress/wordpress-plugin-wp-srvstatus/ for an detailed description.
Translations
Not available at the moment, english only.

WP Server Status

This plugin will display the online/offline status of defined server in your sidebar.

Yahoo! Status Checker vs WP Server Status