Copy all text in a Gnome terminal

Shamelessly copied from arsane on superuser.com (Thanks)

Instead of dragging mouse to select all text:

1. Triple click the last line of current terminal(do not release the mouse).
2. Press SHIFT+HOME key which will lead us to the first line.
3. Drag mouse to the first line.
4. Right click , edit->copy.

See http://superuser.com/a/80175.