highlight-text-copy-to-clipboard-parcellite
sudo apt-get install parcellite
Preferences -> Behavior -> "Use Primary Selection" and "Synchronize Clipboards"
Copy some stuff from terminal, then you can use control + alt + h to see it's there!
Merges 1) the universal "clipboard" (CTRL+C / CTRL+V) 2) the X-Windows "select text" buffer (select text, middle mouse click)