IM Chat Messenger

Yahoo! Multi Messenger allows you to remain online on multiple yahoo ids using multiple instances of yahoo messenger. No need of installation, no need of any other third party softwares, just open the .reg file and Yahoo multimessenger will start working. After running the .reg file, just click the normal yahoo messenger icon to start as many instances as you like. This software is perfect for those who wish to be online under several names.
It works with every version of yahoo messenger. You may have to uncheck the automatic sign in option in the messenger because every new instance will try to login with the same id which will logout you from the previosly opened instance, in this situation you will get a messaage like “You have been logged out as you were logged in on a different machine”.

Download this Yahoo Messenger addon tool from softpedia