With the Messages app on Mac OS X you can easily start screen sharing with another Mac. This is very helpful when you need to assist someone else with a problem on their Mac. You can see their entire screen and can also move their mouse and type on the keyboard.
One thing I find disturbing is that iMessage on the Mac does not support screen sharing. I had been using iMessage for a while now, but was also using Bonjour and Jabber. I had no idea that screen sharing was not using iMessage. So, when using the Messages app on the Mac, you are required to use Bonjour or Jabber.
From the Messages help file:
“You can share screens using AIM (including me.com and Mac.com), Jabber, Google Talk, and Bonjour. You can’t share screens using iMessage or Yahoo!.”
Someday soon I hope that new users of Macs will be able to quickly start using the screen sharing feature with iMessages. Maybe Mavericks will support this soon.