What I like to with the terminal is mess with my brother when he bothers me using ssh. You can make the computer on the other end talk, you can open shock sites like ****** and ******* a couple thousand times, make really horrible songs like "milkshake" or "lean back" play loudly while they are trying to work.
This site explains how to do it pretty well
http://www.macosxhints.com/article.php?story=20030328190234419
Edit: Funny, I didn't think thoes shock site names would be blocked.