This is a great option, I looked at it in the beta demo site. One suggestion, could you alias /msg to the command you created for it? I know I am showing a bit of age but /msg comes very naturally to me in chat programs to send private chats.
In fact with my question I'm just trying to let you become aware of a concret problem : One of the phpfreechat features is to allows nicknames with any kind of characteres, chinese, accent, etc ... and also spaces. When using this kind of commands, with a space as a separator (between 'nickname' and the message content), it make imposible to know where is the real separator as the space character can exists somewhere in the nickname.
The way I manage this problem internaly is to use a hashed (using md5sum) nickname. But this hashed nickname is a unreadable string for human, something like that fdba8e62b9f99621e4caa5b149e3f82b. So I don't want the user type : /msg fdba8e62b9f99621e4caa5b149e3f82b hello, how are you Currently I don't have a user friendly manner to make possible these kind of composed commands.
I don't know if I'm clear, but any ideas are welcomed