Disable system beep. This is one of those things that just annoys me. When I'm typing away at the command line, I make a mistake and I get an annoying beep from the PC speaker. It's easy as pie to get rid of, though. Open up the file /etc/inputrc and you should see a line that says:
set bell-style audible
Change that to:
set bell-style none
and save the file. When you boot up again, that annoying beep is history.