Simply look at the bottom of the screen. You will see "Unity Stamp Company Friends"
Take your cursor over the TOP of the words and click. A screen will pop up that displays all of your new Unity Place Friends and host a LIVE CHAT for you!
Once your chat screen is OPEN you will see a little arrow that points DOWN. That collapses the screen.
Your chat is visible to YOU and all of your FRIENDS. If you don't care to have your friends know you are online simply hit the green button. It will block your existence and leave you in peace! :)