Saw this posted over at Blue's News. Here's the scoop:
Version 0.61 of the Admin Mod for Half-Life is now available on Alfred's Page, offering a plug-in for Half-Life server operators that can give selected administrative server functions to certain users, without giving them access to the server's RCon. The new release adds a workaround for a Counter-Strike bug, and adds the "admin_ban" and "admin_unban" commands.