This block is compatible with PHP-Nuke v6.5 threu v7.6+. Some of the many improvements are Avatars, users Signing up, Admin area options, PM image and link, SQL abstraction layer, xhtml fixes, optimized images (no color loss), now uses security code choice $gfx_chk in config.php, ability to turn on/off the 'forgot password' and 'Total Online' text displays, inbox image is smart (no new messages means no animation, new messages starts animation), totals are aligned right for good looks, if the latest member's nick is too long it drops down to a center in the next row, better wording to encourage people to create an account, admin has a link to logout (it only shows if admin is logged in), and the block dynamically changes looks depending if you are logged in or not.

This screenshot shows option 6 for security code (not shown for user's login) plus the left side is logged out and the right side is admin and user logged in. Also, the 'Total Online' option is set to 0 to hide that stat.