Copy and paste in a terminal with the mouse

[jean.lee at free.fr (Jean Lee)]

Hi all,

Does anybody know what is the name of the tool which is needed to copy 
some text in a terminal window and to paste this text at the end of the 
command line using the mouse ?

It is a basic function but really helpfull and it is not installed on my 
workstation.

I am using Gnome and CentOS 4.1.

Regards,

Jean LEE