How to Find an Invisible User on Yahoo! Messenger
Share Videos in IM Window
Zync plug-in allows you and a friend to watch the same video in sync in the IM window. To play a video from YouTube, Yahoo! Video or Google Video, grab the URL (http://) from the website and type watch [video URL] into your IM text box and send it (ex: watch http://video.yahoo.com/video/play?vid=329037). The best part about Zync is that when the video is playing, you and your friend see the exact same thing at the same time. This makes it much easier to talk about the video.
Share Desktop with your friends.
Unyte Lyte provides 1:1 desktop sharing to Yahoo users. With one click invite contacts from your Yahoo! Messenger list to "see" your desktop.