This simple tutorial is going to show you an indicator applet which collects recent messages sent with libnotify to a notification daemon and displays recent notifications in system tray area.
Install Recent Notifications indicator in Ubuntu 12.04 & 11.10:
To get this indicator, hit Ctrl+Alt+T to open a terminal window, copy and paste this command into terminal and hit enter to add PPA:
sudo add-apt-repository ppa:jconti/recent-notifications
Then update and install the indicator:
sudo apt-get update
sudo apt-get install indicator-notifications
Log out and back in, you’ll see the applet icon in the system tray area.