Installing Yahoo Messenger will also install an extra URI handler in some browser to handle URIs like “ymsgr:”. You can think of this like “mailto:” URI scheme. Below are some example of using this URI scheme.
ymsgr:addfriend? Example: ymsgr:addfriend?myid
ymsgr:sendfile? Example: ymsgr:sendfile?myid
You can play little trick with Yahoo Messenger status by replace the link in your status by “ymsgr:-kill”. If your friend clicked on your status, it will immediately exit Yahoo Messenger.