When you use Ubuntu X11 you at times want to start an application as Root.

In your console you'd use the sudo tool which gives the command temporary super-user powers.

sudo my-command

In Ubuntu Gnome you can do the same using the gksu command. So add an icon, enter the usual information, and for your command, add gksu in front of it. When clicked, you'll first get a prompt asking you your sudo password, then the command is executed as if the root user had started it.

gksu faxanwer ttyS0