Some of you might have tried the Yahoo! Messenger for Windows Vista which has a hidden feature referred to as Matrix mode. Matrix mode expands the tabbed conversations feature of multiple IM windows in Yahoo! Messenger.
First, start a few IM conversations and then drag the bottom tab of one window into another (or can be done by pressing Ctrl + comma ) to condense them into one window as tabs. Now to get the Matrix mode just press Ctrl + Alt + Shift + b which will turn your tabbed conversation window into one single window with a matrix of boxes, each showing an IM conversation.