How do I remove the American Flag icon?

I will never need to switch from the American English version to another language keyboard, so it is not necessary to have the American Flag icon cluttering up my top menu bar. Isn't there a way to remove it? This icon also appears at startup in the login screen. I'm annoyed that I have not been able to figure this out myself. Please help.

G4 Cube Mac OS X (10.4.4)