Alternate working title: How to lose friends and alienate people. 
Bored and was googling how to use javascript in the address bar tonight. Found this life changing gem, http://www.puremango.co.uk/2009/05/hacking-facebook/, which at the bottom mentions some cute emoticons you can use in facebook chat like (^^^) and <(") which render a little shark and penguin, respectively. I know, right!?
Now that your mind is well blown, for my grand finale I will demonstrate how to put smiley faces in the background of your facebook page. I know, just what your life was missing. When you're on facebook, copy and paste this entire line into your address bar and hit enter:
javascript:void(document.getElementById('contentCol').style.background='url("http://mcdermottsolutions.com/smiley.jpg")');
You're welcome.
Pretty harmless stuff. It's visible only to you and will disappear when you refresh the page or anything like that. Tested in firefox, ie8 & ie7.