There are many GIF's out there that are of funny cats and of many different movies. I know that I love the occasional GIF's and especially when they are about math. Here are some great GIF's that you can include in your classroom to spice up lessons and activities for students.
Find more here: http://www.tumblr.com/tagged/math%20gif
Find other great GIF's here: 7 GIF's for Trigonometry