UserOnline Plugin for Wordpress 2.0

This is one of the best plugins I have found for wordpress. The plugin adds a Useronline feature to WordPress.

You can also use it to find out which all bots are online at a particular time. The currently supported bots are Google, MSN, Lycos, Ask Jeeves, Altavista, AllTheWeb, Inktomi, Technorati, Yahoo and many others.

You can download the plugin from here