Imagine this scenario:

You run a command at gnome terminal. This command has made a bunch of outputs to the terminal. After some time, you realize you need the value of a variable (let's say variable_needed) that was printed by the command somewhere in the terminal. How to find it?

KDE terminal used to have a shortcut ctrl+shift+f which searched the terminal output. It seems that gnome-terminal doesn't have it (at least at Ubuntu 10.04.2 LTS). Is there any way of adding it? Is there any other good terminal I could use that has it?

Notice that the output has already been written so I don't want (cannot) run the command again combined with grep, |, >, vim, emacs, etc.