Hey Scribu/Gamerz,
Just a minor feature request: it would be great if the detailed useronline page included the useragent as well; that would make it easier to identify who your visitors are, as well as potentially miscategorized visitors (bot/nonbot) for forwards-compatibility.
It's a one-line change; template-tags.php, line 220 from:
$output .= "<p><strong>#$nr - $name</strong> $user_ip $_on $date<br/>$page_title $current_link $referral_link</p>\n";
to:
$output .= "<p><strong>#$nr - $name</strong> $user_ip $_on $date<br/>$page_title $current_link $referral_link<br/>$user->user_agent</p>\n";