As you may have seen in the preview of Yahoo! Messenger for Windows Vista, tabbed IM windows are coming soon. This feature lets you group multiple conversations into one IM window and use tabs to navigate among them.
As it turns out, there are several hidden features that are built into Yahoo! Messenger, which can be turned on with changes to the Windows registry settings. One of our Messenger engineers, Hung Nguyen, developed some code that when installed, adds tabs to Yahoo! Messenger 8.1 (on Windows XP).
To try it out, first close all the IM windows you have open. Then click the “Turn ON tabs in Yahoo! Messenger” link below. When the download window appears, click the “Run” button and follow the on-screen instructions to install it. The next time you’re in two or more IM conversations at the same time, you’ll see the tabs in action. To close a tab, just right click on it.
Turn ON tabs in Yahoo! Messenger 8.1
Turn OFF tabs in Yahoo! Messenger 8.1