If I'm working in a terminal window in Linux, is there a keyboard shortcut I can use to select output displayed on previous lines? If I select something with the mouse I can copy using Ctrl + Shift + C, but is there a way to select without using the mouse at all. I'm using either Gnome terminal or KDE konsole in Ubuntu desktop.

For example I often need to copy results from a mysql query and then google them.

You can use the screen application and enter copy mode with Ctrl+a, Esc. Start selecting text with Space and end selecting text with Space. Insert text with Ctrl+a, ]