Shoutbox

weeeeeell... u could require that each user has the plugin, then use the notify code to send a simple random number, or the 5 letter hash (i don't know much about hashing so i don't know if u can have a 5 letter hash ), then recievenotify to pick it up and display it in a messagebox.

Of course, you could still fake this (and if you haven't figured out how yet, i'm not telling ), but not as easily as just typing in a message.