Today, i find a really good software with the help of which you can access yahoo messenger,msn messenger,mIRC,ICQ and AIM simultaneously.Trillian is the name of this software.
Audio chat, file transfers, group chats, chat rooms, buddy icons, multiple simultaneous connections to the same network, server-side contact importing, typing notification, direct connection (AIM), proxy support, encrypted messaging (AIM/ICQ), SMS support, tabbed chatting, system-tray notifications and alerts, and privacy settings are the features of Trillian.It can import your buddy lists, and client preferences into its own interface.Trillian is absolutely free. Download it from the link given below:
http://www.ceruleanstudios.com/