Diodon is a simple clipboard manager for GNOME with application indicator support. Aiming to be the best integrated clipboard manager for the Gnome/GTK+ desktop.
Diodon remembers what you copied using ctrl+c, right-click menu, highlight and displays on Ubuntu panel by clicking on the shortcut icon. Then left-click on one to re-copy into clipboard.
Diodon-team ppa provides packages for Ubuntu 10.04/10.10/11.04, open up a terminal and run following three commands:
sudo add-apt-repository ppa:diodon-team/daily sudo apt-get update sudo apt-get install diodon
After that, launch the panel indicator under Applications -> Accessories -> Diodon.